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[[Category:XMPP扩展]]
[[Category:翻译中]]

'''本文的英文原文来自[http://www.xmpp.org/extensions/xep-0045.html XEP-0045]'''

'''XEP-0045: 多用户聊天'''

摘要: 本文定义了一个XMPP协议扩展用于多用户文本会议.即多个XMPP可以在一个房间或频道互相交流信息, 类似互联网中继聊天系统(IRC).还有标准聊天室功能如聊天室的主题和邀请，本协议定义了一个强有力的房间控制模型，包括能够踢和禁止用户，任命主持人和管理员，要求会员或密码才能加入房间，等等。

作者:	Peter Saint-Andre

XMPP扩展协议的版权(1999-2008)归XMPP标准化基金会(XSF)所有

版权:	© 1999 - 2010 XMPP标准化基金会(XSF). 参见[[XEP-0045#法律通告|法律通告]].

状态: 草案

类型: 标准跟踪

版本: 1.24

最后更新日期: 2008-07-16

注意: 这里定义的协议是XMPP标准化基金会的一个草案标准.对本协议的执行是被鼓励的,也适于部署到生产系统,但是在它成为最终标准之前可能还会有一些变动.

==绪论==

传统上, 即时消息被视为由一对一的聊天构成而不是多对多聊天(即所谓"群聊"或"文本会议"). 群聊功能常见于一些系统如 Internet Relay Chat (IRC) 和 流行的IM服务所提供的聊天室功能. Jabber社区早在1999年开发和实施了一个基本的群聊协议. 这个 "groupchat 1.0" 协议为聊天室提供了一个最小功能集但是范围很有限. 本协议(多用户聊天或简称MUC)建立在向后兼容旧的"groupchat 1.0"协议的基础上但是提供高级功能如邀请, 房间主持和管理, 以及专门的房间类型.

==范围==

本文着重于和配置,参与以及管理一个独立的基于文本的会议室相关的通用需求. 这里所指出的需求是应用于单个房间级别的并且是"通用的", 某种意义上它们是在Jabber社区广泛讨论的或在现有的Jabber之外的基于文本的会议环境(例如, 定义在 [http://tools.ietf.org/html/rfc1459 RFC 1459] [[XEP-0045#附录G:备注|1]]中的Internet Relay Chat 和它的继承者: [http://tools.ietf.org/html/rfc2810 RFC 2810] [[XEP-0045#附录G:备注|2]], [http://tools.ietf.org/html/rfc2811 RFC 2811] [[XEP-0045#附录G:备注|3]], [http://tools.ietf.org/html/rfc2812 RFC 2812] [[XEP-0045#附录G:备注|4]], [http://tools.ietf.org/html/rfc2813 RFC 2813] [[XEP-0045#附录G:备注|5]])中已经存在的.

本文明确地不涉及以下需求:

* 房间之间的关系(例如, 房间的层次结构)

* 多用户聊天服务的管理(例如, 管理跨越整个服务级别的权限或注册一个全局可用的房间昵称)；这些用例定义在[http://xmpp.org/extensions/xep-0133.html Service Administration] [[XEP-0045#附录G:备注|6]]

* 个别消息的主持

* 通过房间发送的消息的加密

* 高级特性, 如附加文件给一个房间, 集成白板, 以及和语音或视频聊天服务的接口

* MUC部署和外来的聊天系统(例如, 和IRC网关或现有的其他IM系统)之间的交互

* 在多个MUC部署之间进行镜像或复制

这一受限的范围并非蔑视这些都很有用的主题; 无论如何, 这意味着本文专注于讨论和介绍一个易于理解的协议能够被类似的Jabber客户端和组件开发者实现. 将来的协议当然可能涉及以上提到的这些主题.

==需求==

本文描述了由Jabber现有的多用户聊天服务提供的最小功能集. 为了向后兼容性起见, 本文使用原来的"groupchat 1.0"协议作为基本功能, 包括以下这些:

* 每个房间被标识为 <room@service> (例如, <jdev@conference.jabber.org>), 这里 "room" 是房间的名称而 "service" 是多用户聊天服务运行所在的主机名.

* 在一个房间里每个房客被标识为 <room@service/nick>, 这里 "nick" 是这个房客在这个房间里的昵称,定义于刚加入这个房间的时候，也可以在房客驻留改房间期间修改.

* 一个用户通过发送出席信息给 <room@service/nick> 来加入一个房间（也就是成为房客）.

* 在多用户聊天房间里发送的消息使用特殊的类型"groupchat"并且被寻址于房间本身 (room@service), 然后反映给所有房客.

* 通过发送出席信息给 <room@service/newnick>，一个房客可以改变他或她的房间昵称以及在房间中的可用性状态 .

* 通过发送一个类型为"unavailable"的出席信息给当前的<room@service/nick>，一个房客可以退出房间.

本文追加的特性和功能包括以下这些:

# 本地会话日志(不需要房间内的机器人)
# 允许用户申请房间成员
# 在一个非匿名房间里, 允许房客可以察看(另)一个房客的全JID
# 在一个半匿名房间里, 允许主持人可以察看一个房客的全JID
# 允许只有主持人修改房间主题
# 允许主持人从房间里踢出与会者和游客
# 在一个被主持的房间里,主持人可以授予和撤销发言权(也就是说, 发言的权力), 并且管理发言权列表
# 允许管理员授权和取消主持人权力, 并且管理主持人列表
# 允许管理员在房间禁止用户, 并管理黑名单
# 允许管理员授予和撤销成员权力, 并且管理一个仅限成员的房间的成员列表
# 允许所有者限制房客的数量
# 允许所有者指定其他的所有者(们)
# 允许所有者授予或撤销管理特权, 并管理管理员列表
# 允许所有者销毁房间

另外, 本文提供了协议元素用于支持以下房间类型:

# 公共的或隐藏的
# 持久的或临时的
# 密码保护的或不安全的
# 仅限成员的或开放的
# 主持的或非主持的
# 非匿名的或半匿名的

为了实现这些需求, 本扩展协议需要满足 'http://jabber.org/protocol/muc' 名字空间(以及 在主名字空间URI加上 #owner, #admin, 和 #user 片断).

==术语==

===通用术语===

Affiliation(级别) -- 一个长期存在的和房间之间的联系或连接; 可能的级别有 "owner"(所有者), "admin"(管理者), "member"(成员), 以及 "outcast"(被排斥者) (当然也可能没有级别); 级别从角色来看是唯一的. 一个级别跨越了用户对一个房间的访问期间.

Ban(禁止) -- 从一个房间移除一个用户以使这个用户不能够再进入这个房间 (直到这个禁令被废除为止). 一个被禁止的用户的级别为 "outcast"(被排斥者).

Bare JID(纯JID) -- 一个用户的标识符 <user@host>, 不同于任何已有会话或资源的上下文, 与之相对的是全JID和房间JID.

Full JID(全JID) -- 一个在线用户的标识符 <user@host/resource> , 不同于一个房间的上下文; 与之相对的是纯JID和房间JID.

GC -- 最小的 "groupchat 1.0" 协议[7], Jabber社区于1999年开发; MUC 向后兼容GC.

History(历史) -- 有限数量的消息节, 由当前讨论的上下文提供发送给一个新的房客.

Invitation(邀请) -- 从一个用户发出的特殊消息给另一个用户, 邀请对方加入房间.

IRC -- Internet Relay Chat.

Kick(踢人) -- 临时从一个房间移除一个与会者或游客; 这个用户任何时候都可以再次进入这个房间. 一个被踢的用户的角色是"none".

Logging(记录) -- 存储发生在一个房间的讨论内容用于公开发布到房间背景之外的地方.

Member(成员) -- 一个用户在一个仅限会员的房间内处于"white list"(白名单)内，或已经注册到一个公开的房间. 一个成员级别是"member".

Moderator(主持人) -- 一个房间角色,通常和房间的管理有关但是这个角色可以被赋予非管理员; 可以踢人, 可以授予和撤销发言权, 等等. 一个主持人的角色是"moderator".

MUC -- 本文所定义的基于文本会议的多用户聊天协议.

Occupant(房客) -- 一个房间里的任何Jabber用户 (这是一个 "抽象类" 并且不对应任何特定的角色).

Outcast(被排斥者) -- 一个被某个房间禁止的用户. 一个被排斥者的级别是 "outcast".

Participant(与会者) -- 一个没有管理权限的房客; 在一个被主持的房间里, 参与者更多地被定义为有发言权的 (与之相反的是游客). 一个与会者的角色是"participant".

Private Message(私有消息) -- 从一个房客直接发给另一个房间JID的消息(不是房间本身广播给所有房客的消息).

Role(角色) -- 在一个房间里的一个临时的地位或者权限级别, 对于这个房间中的用户的长期级别来说是唯一的; 可能的角色有 "moderator"（主持人）, "participant"(与会者), 和 "visitor"(游客) (也可能没有预定义的角色). 一个角色仅仅存在于一个房客访问一个房间的期间.

Room(房间) -- 一个虚拟的地方, Jabber用户象征性地加入它, 来和其他用户一起参与一个实时的基于文本的会议.

Room Administrator(房间管理员) -- 一个由房间所有者授权的用户, 可以执行管理功能, 如禁止用户等等; 无论如何, 不允许改变定义的房间特性. 一个管理员的级别是"admin" .

Room ID(房间ID) -- 一个房间JID的节点标识符部分, 它可以是不透明的因而对人类用户没有什么含义(见  语法的商业规则Business Rules for syntax); 与之相对的是房间名.

Room JID(房间JID) -- 在一个房间上下文中的一个房客，以 <room@service/nick> 来标识; 与之相对的是纯JID和全JID.

Room Name(房间名) -- 一个用户友好的, 自然语言的房间名字, 由房间所有者配置并在服务查询中展示; 与之相对的是房间ID.

Room Nickname(房间昵称) -- 房间JID的资源标识符部分(见语法的商业规则); 这是一个房客在这个房间中所呈现的"友好的名字".

Room Owner(房间所有者) -- 建立某个房间的Jabber用户或一个被房间创建者或所有者指派拥有所有者权限(如果允许的话)的Jabber用户; 它被允许改变定义好的房间特性, 也可以执行全部的管理功能. 一个所有者的级别为"owner".

Room Roster(房间名册) -- 一个房间中的所有房客在一个Jabber客户端的展现.

Server(服务器) -- 一个Jabber服务器，可以关联或不关联一个基于文本的会议服务.

Service(服务) -- 一个主机, 提供基于文本的会议的能力; 通常但不必须是一个Jabber服务器的子域(例如, conference.jabber.org).

Subject(主题) -- 一个房间的临时讨论标题.

Visit(访问) -- 一个房间的一个用户的"session"(会话), 当用户进入这个房间时开始(也就是说, 成为一个房客) , 结束于用户离开房间之时.

Visitor(游客) -- 在一个被主持的房间里的一个没有发言权的房客(相反则是一个与会者). 一个游客的角色是"visitor".

Voice(发言权) -- 在一个被主持的房间里, 发送消息给全部房客的权限.

===房间类型===

Fully-Anonymous Room(全匿名房间) -- 一个房间的房客的全JID或纯JID不能被任何人查询到, 包括房间管理员和房间所有者; 这类房间是不推荐的(NOT RECOMMENDED)或不被MUC显式支持, 但是如果一个服务提供适当的配置选项来使用这个协议，这种情况也是有可能的; 相对的则是非匿名房间和半匿名房间.

Hidden Room(隐藏房间) -- 一个无法被任何用户以普通方法如搜索和服务查询来发现的房间; 反义词: 公开(public)房间.

Members-Only Room(仅限会员的房间) -- 如果一个用户不在成员列表中则无法加入的一个房间; 反义词: 开放(open)房间.

Moderated Room(被主持的房间) -- 只有有"发言权"的用户才可以发送消息给所有房客的房间; 反义词: 非主持的Unmoderated房间.

Non-Anonymous Room(非匿名房间) -- 一个房客的全JID会暴露给所有其他房客的房间, 尽管房客可以选择任何期望的房间昵称; 相对的是半匿名房间和全匿名房间.

Open Room(开放房间) -- 任何人可以加入而不需要在成员列表中的房间; 反义词: 仅限会员的房间.

Password-Protected Room(密码保护房间) -- 一个用户必须提供正确密码才能加入的房间; 反义词: 非保密房间.

Persistent Room(持久房间) -- 如果最后一个房客退出也不会被销毁的房间; 反义词: 临时房间.

Public Room(公开房间) -- 用户可以通过普通方法如搜索和服务查询来发现的房间; 反义词: 隐藏房间.

Semi-Anonymous Room(半匿名房间) -- 一个房客的全JID只能被房间管理员发现的房间; 相对的是全匿名房间和非匿名房间.

Temporary Room(临时房间) -- 如果最后一个房客退出就会被销毁的房间; 反义词: 持久房间.

Unmoderated Room(非主持的房间) -- 任何房客都被允许发送消息给所有房客的房间; 反义词: 被主持的房间.

Unsecured Room(非保密房间) -- 任何人不需要提供密码就可以进入的房间; 反义词: 密码保护房间.

===4.3 人物===

本文的大部分例子使用了 the scenario of the witches' meeting held in a dark cave at the beginning of Act IV, Scene I of Shakespeare's Macbeth, 在这里代表"darkcave@macbeth.shakespeare.lit"聊天室. 人物如下:

'''表1: 剧中人'''

{|border="1" cellspacing="0" 
!房间昵称 !!全 JID !!级别
|-
|firstwitch ||crone1@shakespeare.lit/desktop ||所有者
|-
|secondwitch ||wiccarocks@shakespeare.lit/laptop ||管理员
|-
|thirdwitch ||hag66@shakespeare.lit/pda ||无
|}

==角色和级别==

有两个尺度我们可以用来衡量一个用户的连接或在一个房间的地位. 一个是用户和一个房间的长期的级别 -- 例如, 一个用户的状态是一个所有者或一个被排斥者. 另一个是当一个用户驻留于一个聊天室的时候的角色 -- 例如, 一个房客的地位是一个主持人,有权利踢出游客和与会者. 这两个尺度各自都是唯一的, 因为一个级别是跨越访问的, 而一个角色只存在于一次访问期间. 另外, 在角色和级别之间没有一对一的对应关系; 例如, 某个不从属于某房间的人可能成为一个(临时的)主持人, 一个成员可能在一个被主持的房间中是一个与会者或游客者. 这些概念以下全面解释.

===角色===

以下是已定义的角色:

'''表2: 角色'''
{|border="1" cellspacing="0"
!名称 !!支持
|-
| 主持人   ||必需的 
|-
| 无       ||缺少角色
|-
| 与会者   ||必需的
|-
| 游客     ||推荐的
|}

角色是临时的,它不一定要在用户对房间的访问中持久化,它可以(MAY)在一个房客访问房间期间改变. 一个实现可以(MAY)在一次访问期间持久化角色并且应该(SHOULD)在被主持的房间这样做 (因为在游客和与会者之间,唯一性对一个被被主持的房间是很关键的).

在角色和级别之间没有一对一的映射(例如, 一个成员可以是一个与会者或一个游客).

在房间会话中,一个主持人是最有权力的房客, 它能在某种程度走上管理房间的其他房客的角色. 一个与会者的权力小于一个主持人, 尽管他或她有权发言. 在一个被主持的房间会话中游客是一个更受限制的角色, 因为访问者不允许发送消息给所有房客.

角色的授予,撤销, 和维护是基于房客的房间昵称或全JID,而不是纯JID. 和这些角色相关的权限，还有角色改变触发的动作, 定义在下文中.

所有在房间中生成或反射的出席信息中关于角色的信息必须(MUST)被发送,从而发送给房客们.

====权限====

大部分情况下, 角色存在于一个层次中. 例如, 一个与会者可以做任何游客能做的事, 而一个主持人可以做任何与会者能做的事. 每个角色拥有下一级角色所没有的权限; 这些权限定义于下表作为缺省值(一个实现可以(MAY)提供配置选项来重载这些缺省值).

'''表3: 和角色相关的权限'''

{|border="1" cellspacing="0" 
!权限 !!无 !!游客 !!与会者 !!主持人
|-
|在房间中出席 ||否 ||是 ||是 ||是
|-
|接收消息 ||否 ||是 ||是 ||是
|-
|接收房客出席信息 ||否 ||是* ||是 ||是
|-
|出席信息广播到房间 ||否 ||是* ||是 ||是
|-
|改变可用性状态 ||否 ||是 ||是 ||是
|-
|改变房间昵称 ||否 ||是* ||是 ||是
|-
|发送私人消息 ||否 ||是* ||是 ||是
|-
|邀请其他用户 ||否 ||是* ||是* ||是
|-
|发送消息给所有人 ||否 ||否** ||是 ||是
|-
|修改标题 ||否 ||否* ||是* ||是
|-
|踢出与会者和游客 ||否 ||否 ||否 ||是
|-
|授予发言权 ||否 ||否 ||否 ||是
|-
|撤销发言权 ||否 ||否 ||否 ||是***
|}

* 缺省; 设定配置时可以(MAY)修改这个权限.

** 一个实现可以(MAY)在非主持的房间里缺省地授予发言权给游客.

*** 主持人不能(MUST NOT)从一个管理员或所有者收回发言权.

====变更角色====

一个房客的角色变更方法是定义好的. 有时候房客自己的动作导致变更 (例如, 加入或退出房间), 反之有时候由主持人,管理员或所有者的动作导致变更. 如果一个房客的角色改变了, 一个 MUC 服务实现必须(MUST)变更这个房客的角色来反映这个变更并且传达这个变更给所有房客. 角色的变更和它们触发的动作定义于下表.

'''表4: 角色状态表'''

{|border="1" cellspacing="0" 
!> !!无 !!游客 !!与会者 !!主持人
|-
|无 ||-- ||进入被主持的房间 ||进入非主持的房间 ||管理员或所有者进入房间
|-
|游客 ||退出房间或被主持人踢出房间 ||-- ||主持人授予发言权 ||管理员或所有者授予主持人权限
|-
|与会者 ||退出房间或被主持人踢出房间 ||主持人撤销发言权	|-- ||管理员或所有者授予主持人权限
|-
|主持人	||退出房间 ||管理员或所有者改变角色成为游客* ||管理员或所有者改变角色成为与会者或撤销主持人权限* ||--
|}

* 一个主持人不能(MUST NOT)从一个级别属于等于或高于主持人的房客那里收回主持人权限.

注意: 特定的角色一般暗含特定的权限. 例如, 一个管理员或所有者自动成为一个主持人, 所以如果一个房客被授予管理员地位那么这个房客事实上将被授予主持人权限; 类似的, 当一个房客成为一个被主持的房间的成员, 这个房客自动拥有一个与会者的角色. 无论如何, 失去管理员地位并不足以意味这个房客不再是主持人 (因为只要是与会者就可能成为一个主持人). 因此, 当一个房客被授予特定的级别的时候所拥有的角色是固定的, 反之当一个房客失去一个特定的级别它的角色是不确定的并取决于(服务的)实现. 因为一个客户端无法预料是否在撤销某个级别之后这个角色成为什么, 如果它不想同时移除管理员/所有者权限和主持人角色, 那么除了级别变更之外它还必须特意请求角色变更.

===级别===

已定义了以下级别:

# 所有者
# 管理员
# 成员
# 被排斥者
# 无 (缺少级别)

必须支持"所有者"这个级别,推荐支持"管理员","成员","被排斥者"的级别.（"无"表示缺少级别)

这些级别是长时间的跨越一个用户对这个房间的访问期间的并且不受房间里事件的影响. 而且, 这些级别和一个房客在房间中的角色之间没有一对一的映射关系. 级别被授予,撤销, 和维护都是基于这个用户的纯 JID.

如果一个没有已定义的级别的用户进入一个房间, 这个用户的级别被定义为"无"; 无论如何, 这个级别不能跨越(多次的)访问 (也就是说, 一个服务不会跨越访问维护一个 "无 列表").

"成员"级别为房间所有者或管理员提供了一个方法来指定一个"白名单",其中的用户被允许加入一个仅供会员的房间. 当一个成员加入了一个仅供会员的房间, 他或她的级别不会改变, 无论他或她的角色是什么. 成员级别也为用户提供一个方法来高效地注册一个开放的房间并在某种方式意义上保持和那个房间的联系(例如可能在房间里预留那个用户的昵称).

一个被排斥者就是一个被从房间踢出来并且不允许进入那个房间的用户.

关于级别的信息必须(MUST)由房间生成或反射到所有的出席信息节之中发送给房客们.

====权限====

大部分情况下, 级别存在一个层次结构. 例如, 一个所有者可以做任何管理员能做的事情, 而一个管理员可以做任何成员能做的事情. 每个级别拥有其下一级级别所没有的权限; 这些权限定义在下表中.

'''表5: 和级别相关的权限'''

{|border="1" cellspacing="0" 
!权限 !!Outcast(被排斥者) !!None(无) !!Member(成员) !!Admin(管理员) !!Owner(所有者)
|-
|进入房间 ||否 ||是* ||是 ||是 ||是
|-
|注册一个开放的房间 ||否 ||是 ||N/A ||N/A ||N/A
|-
|接收成员列表 ||否 ||否** ||是 ||是 ||是
|-
|加入一个仅限会员的房间 ||否 ||否 ||是* ||是 ||是
|-
|踢出成员并把用户的级别删除	||否 ||否 ||否 ||是 ||是
|-
|编辑成员列表 ||否 ||否 ||否 ||是 ||是
|-
|编辑主持人列表 ||否 ||否 ||否 ||是** ||是**
|-
|编辑管理员列表 ||否 ||否 ||否 ||否 ||是
|-
|编辑所有者列表 ||否 ||否 ||否 ||否 ||是
|-
|变更房间定义 ||否 ||否 ||否 ||否 ||是
|-
|销毁房间	||否 ||否 ||否 ||否 ||是
|}

* 作为缺省值, 一个无级别的用户进入一个被主持的房间的角色是一个游客, 而进入一个开放的房间的角色是一个与会者. 一个成员进入一个房间的角色是与会者. 一个管理员或所有者进入房间的角色是一个主持人.

** 一个管理员或所有者不能(MUST NOT)撤销另一个管理员或所有者的权限.

====变更级别====

一个用户的级别变更方法已经定义得很完善. 有时用户自己的动作导致这些变更(例如, 注册为一个房间的新成员), 反之有时候一个管理员或所有者的动作导致了这些变更. 如果一个用户的级别改变了, 一个MUC服务实现必须(MUST)变更这个用户的级别来反射这一变更并通知所有房客. 级别变更和他们触发的动作定义在下表中.

'''表 6: 级别状态表'''

{|border="1" cellspacing="0" 
|  ||被排斥者(Outcast) ||无(None) ||成员(Member) ||管理员(Admin) ||所有者(Owner)
|-
|被排斥者(Outcast) ||-- ||管理员或所有者移除屏蔽 ||管理员或所有者增加用户到成员列表 ||所有者增加用户到管理员列表 ||所有者增加用户到所有者列表
|-
|无(None) ||管理员或所有者使用屏蔽 ||-- ||管理员或所有者增加用户到成员列表, 或用户注册一个成员(如果允许) ||所有者增加用户到管理员列表 ||所有者增加用户到所有者列表
|-
|成员(Member) ||管理员或所有者使用屏蔽 ||管理员或所有者变更级别为"none" ||-- ||所有者增加用户到管理员列表 ||所有者增加用户到所有者列表
|-
|管理员(Admin) ||所有者使用屏蔽 ||所有者变更级别为"none" ||所有者变更级别为"member" ||-- ||所有者增加用户到所有者列表
|-
|所有者(Owner) ||所有者使用屏蔽 ||所有者变更级别为"none" ||所有者变更级别为"member" ||所有者变更级别为"admin" ||--
|}

==实体用例==

一个MUC实现必须(MUST)支持[http://xmpp.org/extensions/xep-0030.html 服务发现] [[XEP-0045#附录G:备注|7]].

===MUC的发现组件支持===

一个Jabber实体可能希望发现是否一个服务实现了多用户聊天协议; 为了达到这个目的, 它发送一个服务发现信息("disco#info")查询给这组件的JID:

'''例子 1. 用户通过Disco查询聊天服务是否支持MUC'''

<source lang="xml">
<iq from='hag66@shakespeare.lit/pda'
    id='disco1'
    to='macbeth.shakespeare.lit'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>
</source>

服务必须(MUST)返回它的的身份和它所支持的特性:

'''例子 2. 服务返回Disco Info结果'''

<source lang="xml">
<iq from='macbeth.shakespeare.lit'
    id='disco1'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='conference'
        name='Macbeth Chat Service'
        type='text'/>
    <feature var='http://jabber.org/protocol/muc'/>
  </query>
</iq>
</source>

注意: 因为MUC是旧的"groupchat 1.0"协议的超集, 一个MUC服务不应该(SHOULD NOT)返回一个<feature var='gc-1.0'/>条目在一个disco#info结果中.

===发现房间===

发现服务条目("disco#items")协议使得一个用户可以向一个服务查询相关的条目列表, 在一个聊天服务中这包含这个服务所承载的所有特定房间的集合.

'''例子 3. 用户向聊天服务查询房间'''

<source lang="xml">
<iq from='hag66@shakespeare.lit/pda'
    id='disco2'
    to='macbeth.shakespeare.lit'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#items'/>
</iq>
</source>

服务应该(SHOULD)返回它承载的所有房间的列表.

'''例子 4. 服务返回Disco Item结果'''

<source lang="xml">
<iq from='macbeth.shakespeare.lit'
    id='disco2'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#items'>
    <item jid='heath@macbeth.shakespeare.lit'
          name='A Lonely Heath'/>
    <item jid='darkcave@macbeth.shakespeare.lit'
          name='A Dark Cave'/>
    <item jid='forres@macbeth.shakespeare.lit'
          name='The Palace'/>
    <item jid='inverness@macbeth.shakespeare.lit'
          name='Macbeth&apos;s Castle'/>
  </query>
</iq>
</source>

如果全部房间的列表太大(详见[XMPP文档列表/XMPP扩展/XEP-0030]), 服务可以(MAY)只返回部分的房间列表.如果这样做了, 它应该 SHOULD 包含一个 <set/> 元素 (定义在 [http://xmpp.org/extensions/xep-0059.html Result Set Management] [[XEP-0045#附录G:备注|8]]) 以表明这个列表不是全部的结果集.

'''例子 5. 服务返回Disco Item结果的部分列表'''

<source lang="xml">
<iq from='rooms.shakespeare.lit'
    id='disco-rsm-1'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#items'>
    <item jid='alls-well-that-ends-well@rooms.shakespeare.lit'/>
    <item jid='as-you-like-it@rooms.shakespeare.lit'/>
    <item jid='cleopatra@rooms.shakespeare.lit'/>
    <item jid='comedy-of-errors@rooms.shakespeare.lit'/>
    <item jid='coriolanus@rooms.shakespeare.lit'/>
    <item jid='cymbeline@rooms.shakespeare.lit'/>
    <item jid='hamlet@rooms.shakespeare.lit'/>
    <item jid='henry-the-fourth-one@rooms.shakespeare.lit'/>
    <item jid='henry-the-fourth-two@rooms.shakespeare.lit'/>
    <item jid='henry-the-fifth@rooms.shakespeare.lit'/>
    <set xmlns='http://jabber.org/protocol/rsm'>
      <first index='0'>alls-well-that-ends-well@rooms.shakespeare.lit</first>
      <last>henry-the-fifth@rooms.shakespeare.lit</last>
      <count>37</count>
    </set>
  </query>
</iq>
</source>

===查询房间信息===

使用 disco#info 协议, 一个用户也可以查询一个特定房间的详情. 为了在进入房间之间确定这个房间的隐私和安全配置用户应该(SHOULD)这样做(详见 [XEP-0045#安全事项｜安全事项］).

'''例子 6. 用户查询特定聊天室的信息'''

<source lang="xml">
<iq from='hag66@shakespeare.lit/pda'
    id='disco3'
    to='darkcave@macbeth.shakespeare.lit'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>
</source>

房间必须(MUST)返回它的标识并且应该(SHOULD)返回它支持的特性:

'''例子 7. 房间返回查询信息结果'''

<source lang="xml">
<iq from='darkcave@macbeth.shakespeare.lit'
    id='disco3'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='conference'
        name='A Dark Cave'
        type='text'/>
    <feature var='http://jabber.org/protocol/muc'/>
    <feature var='muc_passwordprotected'/>
    <feature var='muc_hidden'/>
    <feature var='muc_temporary'/>
    <feature var='muc_open'/>
    <feature var='muc_unmoderated'/>
    <feature var='muc_nonanonymous'/>
  </query>
</iq>
</source>

注意: 因为 MUC 是旧的 "groupchat 1.0" 协议的超集, 一个 MUC 房间不应该(SHOULD NOT)在一个disco#info结果中返回<feature var='gc-1.0'/>条目. 房间应该(SHOULD)返回它支持的实质的有意义的特性, 例如密码保护和房间主持(这些特性被完整地列入了特性注册, 由[http://xmpp.org/registrar/ XMPP Registrar]维护; 也见于本文的[[XEP-0045#registrar|XMPP注册]] 章节).

一个聊天室可以(MAY)使用[http://xmpp.org/extensions/xep-0128.html 服务查询扩展] [[XEP-0045#附录G:备注|9]]在它的disco#info应答中返回更详细的信息, 通过包含一个隐含的FORM_TYPE属性值"http://jabber.org/protocol/muc#roominfo"来标识. 这些信息可能包括关于一个房间的更详细的描述, 当前的房间标题, 以及这个房间当前的房客数量:

'''例子 8. 房间返回扩展的查询信息结果'''

<source lang="xml">
<iq from='darkcave@macbeth.shakespeare.lit'
    id='disco3a'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='conference'
        name='A Dark Cave'
        type='text'/>
    <feature var='http://jabber.org/protocol/muc'/>
    <feature var='muc_passwordprotected'/>
    <feature var='muc_hidden'/>
    <feature var='muc_temporary'/>
    <feature var='muc_open'/>
    <feature var='muc_unmoderated'/>
    <feature var='muc_nonanonymous'/>
    <x xmlns='jabber:x:data' type='result'>
      <field var='FORM_TYPE' type='hidden'>
        <value>http://jabber.org/protocol/muc#roominfo</value>
      </field>
      <field var='muc#roominfo_description' label='Description'>
        <value>The place for all good witches!</value>
      </field>
      <field var='muc#roominfo_changesubject' label='Whether Occupants May Change the Subject'>
        <value>true</value>
      </field>
      <field var='muc#roominfo_contactjid' label='Contact Addresses'>
        <value>crone1@shakespeare.lit</value>
      </field>
      <field var='muc#roominfo_subject' label='Subject'>
        <value>Spells</value>
      </field>
      <field var='muc#roominfo_occupants' label='Number of occupants'>
        <value>3</value>
      </field>
      <field var='muc#roominfo_lang' label='Language of discussion'>
        <value>en</value>
      </field>
      <field var='muc#roominfo_logs' label='URL for discussion logs'>
        <value>http://www.shakespeare.lit/chatlogs/darkcave/</value>
      </field>
      <field var='muc#roominfo_pubsub' label='Associated pubsub node'>
        <value>xmpp:pubsub.shakespeare.lit?node=chatrooms/darkcave</value>
      </field>
    </x>
  </query>
</iq>
</source>

某些扩展的房间信息可能是动态生成的(例如, 讨论记录的URL地址, 它可能取决于服务器那一层的配置); 反之另一些信息则可能基于房间那一层的配置,任何定义在[[XEP-0045#附录G:备注|muc#roomconfig FORM_TYPE]] 里的字段都可以用于扩展服务发现的字段(如上文所示的 muc#roomconfig_changesubject 字段).

注意: 前述 'http://jabber.org/protocol/muc#roominfo' FORM_TYPE的扩展服务发现字段将来还可以扩充(通过本文的[[XEP-0045#附录G:备注|字段标准化]]章节描述的机制).

===查询房间条目===

一个用户也可以(MAY)向一个特定的聊天室查询和它相关的条目:

'''例子 8. 用户查询和一个特定聊天室相关的条目'''

<source lang="xml">
<iq from='hag66@shakespeare.lit/pda'
    id='disco4'
    to='darkcave@macbeth.shakespeare.lit'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#items'/>
</iq>
</source>

一个实现可以(MAY)返回现有驻留者的列表(如果那信息是公开可用的话), 或不返回列表(如果那信息是私有的).

'''例子 9. 房间返回查询条目结果(条目是公开的)'''

<source lang="xml">
<iq from='darkcave@macbeth.shakespeare.lit'
    id='disco4'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#items'>
    <item jid='darkcave@macbeth.shakespeare.lit/firstwitch'/>
    <item jid='darkcave@macbeth.shakespeare.lit/secondwitch'/>
  </query>
</iq>
</source>

注意: 这些 <item/> 元素由 disco#items 名字空间限定, 而不是 muc 名字空间; 这意味着他们不能拥有 'affiliation' 或 'role' 属性, 例如.

'''例子 10. 房间返回空的查询条目结果(条目是私有的)'''

<source lang="xml">
<iq from='darkcave@macbeth.shakespeare.lit'
    id='disco4'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#items'/>
</iq>
</source>

===查询一个房间的驻留者===

如果一个非驻留者试图发送一个查询请求给一个<room@service/nick>类型的地址, 一个 MUC 服务应该(SHOULD)返回这个请求给这个实体并指明一个<bad-request/>错误条件. 如果一个驻留者发送这样一个请求, 服务可以(MAY)把它传递给预订的接收者; 详见本文的 实施指南章节Implementation Guidelines.

===查询客户端对MUC的支持===

一个 Jabber 用户可能想发现这个用户的某个联系人是否支持多用户聊天协议. 这可以使用服务发现(协议)来完成.

'''例子 11. 用户查询联系人对于 MUC 的支持'''

<source lang="xml">
<iq from='hag66@shakespeare.lit/pda'
    id='disco5'
    to='wiccarocks@shakespeare.lit/laptop'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>
</source>

客户端应该(SHOULD)返回它的标识和它支持的特性:

'''例子 12. 联系人返回发现信息结果'''

<source lang="xml">
<iq from='wiccarocks@shakespeare.lit/laptop'
    id='disco5'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='client'
        type='pc'/>
    ...
    <feature var='http://jabber.org/protocol/muc'/>
    ...
  </query>
</iq>
</source>

一个用户也可能查询一个联系人在哪个房间. 这可以通过特定服务发现节点'http://jabber.org/protocol/muc#rooms'查询联系人的全JID(<user@host/resource>)来完成 :

'''例子 13. 用户在当前房间查询联系人'''

<source lang="xml">
<iq from='hag66@shakespeare.lit/pda'
    id='rooms1'
    to='wiccarocks@shakespeare.lit/laptop'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#items'
         node='http://jabber.org/protocol/muc#rooms'/>
</iq>
</source>

'''例子 14. 联系人返回房间查询结果'''

<source lang="xml">
<iq from='wiccarocks@shakespeare.lit/laptop'
    id='rooms1'
    to='hag66@shakespeare.lit/pda'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#items'
         node='http://jabber.org/protocol/muc#rooms'/>
    <item jid='darkcave@macbeth.shakespeare.lit'/>
    <item jid='characters@conference.shakespeare.lit'/>
  </query>
</iq>
</source>

可选择的, 联系人可以(MAY)把它的房间昵称作为'name'属性的值返回:

<source lang="xml">
    ...
    <item jid='darkcave@macbeth.shakespeare.lit'
          name='secondwitch'/>
    ...
</source>

==驻留者用例==

在一个多用户聊天环境中主要的行为者是驻留者, 它可以被认为存在于一个多用户聊天室"之内"并且参与那个房间的讨论 (在本协议中, 参与者和访问者"仅仅"被认为是驻留者, 因为他们不拥有管理员权限). 为了更加清晰起见, 本文中的协议元素中涉及到驻留者的用例分为以下三类:

# 现存于 "groupchat 1.0" 协议的最小功能集
# 对于 "groupchat 1.0" 协议向前兼容的应用, 如处理一些和新房间类型有关的错误
# 用来处理"groupchat 1.0"协议未涉及的功能的额外的协议元素(房间邀请, 房间密码, 和房间角色及从属关系相关的扩展出席信息); 在'http://jabber.org/protocol/muc#user'名字空间

注意: 这里所有客户端生成的例子是从服务的角度来展示的, 所以所有由服务收到的节都包含一个'from'属性来表达发送者的全JID(由一个通用的Jabber路由或会话管理者加入). 另外, 通常的表示请求已被完成的 IQ 结果节(如 RFC 3920 \[9\]中所要求的)未被展示.

===进入一个房间===

====群聊1.0协议====

为了参加一个多用户聊天室的讨论, 一个Jabber用户必须(MUST)首先进入一个房间成为一个驻留者. 在旧的"groupchat 1.0"协议中, 这是通过发送出席信息<room@service/nick>来实现的, 这里"room"是房间的 ID, "service" 是聊天服务的主机名, "nick" 是这个用户在这房间里预期的昵称:

'''例子 15. Jabber用户进入一个房间(Groupchat 1.0)'''

<source lang="xml">
<presence
    from='hag66@shakespeare.lit/pda'
    to='darkcave@macbeth.shakespeare.lit/thirdwitch'/>
</source>

在这个例子中, 一个全JID为"hag66@shakespeare.lit/pda"的用户请求用昵称"thirdwitch"进入位于"macbeth.shakespeare.lit"聊天服务的房间"darkcave".

如果用户未指定一个房间昵称, 服务应该(SHOULD)返回一个<jid-malformed/>错误:

'''例子 16. Jabber用户进入一个房间(Groupchat 1.0)'''

<source lang="xml">
<presence
    from='darkcave@macbeth.shakespeare.lit'
    to='hag66@shakespeare.lit/pda'
    type='error'>
  <error code='400' type='modify'>
    <jid-malformed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
  </error>
</presence>
</source>

====基本MUC协议====

兼容的多用户聊天服务必须（MUST）接受知道"groupchat 1.0" (GC)协议或multi-user chat (MUC)协议的任何客户端发出上述请求进入会议室; 无论如何, MUC 客户端应该(SHOULD)声明他们的有能力支持 MUC 协议, 方法是在出席信息节里面包含一个空的 <x/> 元素, 满足名字空间 'http://jabber.org/protocol/muc'  (注意不需要 '#user' 部分):

'''例子 17. Jabber用户进入一个房间(Multi-User Chat)'''

<source lang="xml">
<presence
    from="hag66@shakespeare.lit/pda"
    to='darkcave@macbeth.shakespeare.lit/thirdwitch'>
  <x xmlns='http://jabber.org/protocol/muc'/>
</presence>
</source>

在尝试进入房间之间, 一个兼容MUC的客户端应该(SHOULD)首先查询它的保留的房间昵称 (如果有的话), 接下来的协议本文中的 Discovering Reserved Room Nickname 章节对此作了定义.

====出席信息广播====

如果服务能够添加用户到房间, 它必须(MUST)从所有现存的驻留者的房间JID发送出席信息给新的驻留者的全JID, 包括扩展的关于角色的出席信息, 一个符合 'http://jabber.org/protocol/muc#user' 名字空间的<x/> 元素并包含一个<item/>子元素, 这个子元素的'role'属性值设为"moderator", "participant", 或"visitor", 这个子元素的'affiliation'属性值设为"owner", "admin", "member", 或 "none" 中的一个:

'''例子 18. 服务从现有的驻留者发送出席信息给新的驻留者'''

<source lang="xml">
<presence
    from='darkcave@macbeth.shakespeare.lit/firstwitch'
    to='hag66@shakespeare.lit/pda'>
  <x xmlns='http://jabber.org/protocol/muc#user'>
    <item affiliation='owner' role='moderator'/>
  </x>
</presence>
<presence
    from='darkcave@macbeth.shakespeare.lit/secondwitch'
    to='hag66@shakespeare.lit/pda'>
  <x xmlns='http://jabber.org/protocol/muc#user'>
    <item affiliation='admin' role='moderator'/>
  </x>
</presence>
</source>

这个示例中, 用户已从前一个例子进入房间, 有两个人已经进入房间: 一个是昵称为"firstwitch"的(房间拥有者), 另一个是昵称为"secondwitch"的(房间管理员).

服务也必须(MUST)从新进入驻留者房间JID向所有驻留者JID发送出席信息(含新驻留者):

示例:19. 服务发送新驻留者的出席信息给所有驻留者

<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

  </x>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='wiccarocks@shakespeare.lit/laptop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

  </x>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

    <status code='110'/>

  </x>

</presence>

      



In this example, initial room presence is being sent from the new occupant (thirdwitch) to all occupants, including the new occupant. As shown in the last stanza, the presence sent by the room to a user from itself as an occupant SHOULD include a status code of 110 so that the user knows this presence refers to itself as an occupant.



The service MAY rewrite the new occupant's roomnick (e.g., if roomnicks are locked down). If the service does not accept the new occupant's requested roomnick but instead assigns a new roomnick, it MUST include a status code of "210" in the presence broadcast that it sends to the new occupant.



Example 20. Service Sends New Occupant's Presence to New Occupant



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

    <status code='110'/>

    <status code='210'/>

  </x>

</presence>

      



Note: The order of the presence stanzas sent to the new occupant is important. The service MUST first send the complete list of the existing occupants to the new occupant and only then send the new occupant's own presence to the new occupant. This helps the client know when it has received the complete "room roster".



After sending the presence broadcast (and only after doing so), the service may then send discussion history, live messages, presence updates, and other in-room traffic.

7.1.4 Default Roles



The following table summarizes the initial default roles that a service should set based on the user's affiliation (there is no role associated with the "outcast" affiliation, since such users are not allowed to enter the room).



Table 6: Initial Role Based on Affiliation

Room Type 	None 	Member 	Admin 	Owner

Moderated 	Visitor 	Participant 	Moderator 	Moderator

Unmoderated 	Participant 	Participant 	Moderator 	Moderator

Members-Only 	N/A * 	Participant 	Moderator 	Moderator

Open 	Participant 	Participant 	Moderator 	Moderator



* Entry is not permitted.

7.1.5 Non-Anonymous Rooms



If the room is non-anonymous, the service MUST send the new occupant's full JID to all occupants using extended presence information in an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with a 'jid' attribute specifying the occupant's full JID:



Example 21. Service Sends Full JID to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

.

.

.

      



If the user is entering a room that is non-anonymous (i.e., which informs all occupants of each occupant's full JID as shown above), the service SHOULD allow the user to enter the room but MUST also warn the user that the room is not anonymous. This SHOULD be done by including a status code of "100" in the initial presence that the room sends to the new occupant:



Example 22. Service Sends New Occupant's Presence to New Occupant



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

    <status code='100'/>

    <status code='110'/>

    <status code='210'/>

  </x>

</presence>

      



However, it MAY be done by sending a message of type "groupchat" to the new occupant containing an <x/> child with a <status/> element that has the 'code' attribute set to a value of "100":



Example 23. Service Warns New Occupant About Lack of Anonymity



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='groupchat'>

  <body>This room is not anonymous.</body>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <status code='100'/>

  </x>

</message>

      



The inclusion of the status code assists clients in presenting their own notification messages (e.g., information appropriate to the user's locality).

7.1.6 Semi-Anonymous Rooms



If the room is semi-anonymous, the service MUST send the new occupant's full JID in the format shown above only to those occupants with a role of "moderator".



(Note: All subsequent examples include the 'jid' attribute for each <item/> element, even though this information is not sent to non-moderators in semi-anonymous rooms.)

7.1.7 Password-Protected Rooms



If the room requires a password and the user did not supply one (or the password provided is incorrect), the service MUST deny access to the room and inform the user that they are unauthorized; this is done by returning a presence stanza of type "error" specifying a <not-authorized/> error:



Example 24. Service Denies Access Because No Password Provided



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='401' type='auth'>

    <not-authorized xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



Passwords SHOULD be supplied with the presence stanza sent when entering the room, contained within an <x/> element qualified by the 'http://jabber.org/protocol/muc' namespace and containing a <password/> child. Passwords are to be sent as cleartext; no other authentication methods are supported at this time, and any such authentication or authorization methods shall be defined in a separate specification (see the Security Considerations section of this document).



Example 25. User Provides Password On Entering a Room



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'>

    <password>cauldronburn</password>

  </x>

</presence>

      



7.1.8 Members-Only Rooms



If the room is members-only but the user is not on the member list, the service MUST deny access to the room and inform the user that they are not allowed to enter the room; this is done by returning a presence stanza of type "error" specifying a <registration-required/> error condition:



Example 26. Service Denies Access Because User Is Not on Member List



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='407' type='auth'>

    <registration-required xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



7.1.9 Banned Users



If the user has been banned from the room (i.e., has an affiliation of "outcast"), the service MUST deny access to the room and inform the user of the fact that he or she is banned; this is done by returning a presence stanza of type "error" specifying a <forbidden/> error condition:



Example 27. Service Denies Access Because User is Banned



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



7.1.10 Nickname Conflict



If the room already contains another user with the nickname desired by the user seeking to enter the room (or if the nickname is reserved by another user on the member list), the service MUST deny access to the room and inform the user of the conflict; this is done by returning a presence stanza of type "error" specifying a <conflict/> error condition:



Example 28. Service Denies Access Because of Nick Conflict



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='409' type='cancel'>

    <conflict xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



However, if the bare JID (<node@domain.tld>) of the present occupant matches the bare JID of the user seeking to enter the room, then the service SHOULD allow entry to the user, so that the user has two (or more) in-room "sessions" with the same roomnick, one for each resource. If a service allows more than one occupant with the same bare JID and the same room nickname, it SHOULD route in-room messages to all of the user's resources and allow all of the user's resources to send messages to the room; it is up to the implementation to determine how to appropriately handle presence from the user's resources and how to route private messages to all or only one resource (based on presence priority or some other algorithm).

7.1.11 Max Users



If the room has reached its maximum number of users, the service SHOULD deny access to the room and inform the user of the restriction; this is done by returning a presence stanza of type "error" specifying a <service-unavailable/> error condition:



Example 29. Service Informs User that Room Occupant Limit Has Been Reached



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='503' type='wait'>

    <service-unavailable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



Alternatively, the room could kick an "idle user" in order to free up space. Also, a room MUST always allow entry by a room admin or owner.

7.1.12 Locked Room



If a user attempts to enter a room while it is "locked" (i.e., before the room creator provides an initial configuration and therefore before the room officially exists), the service MUST refuse entry and return an <item-not-found/> error to the user:



Example 30. Service Denies Access Because Room Does Not Exist



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='404' type='cancel'>

    <item-not-found xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



7.1.13 Nonexistent Room



If the room does not already exist when the user seeks to enter it, the service SHOULD create it; however, this is not required, since an implementation or deployment MAY choose to restrict the privilege of creating rooms. For details, see the Creating a Room section of this document.

7.1.14 Room Logging



If the user is entering a room in which the discussions are logged to a public archive (often accessible via HTTP), the service SHOULD allow the user to enter the room but MUST also warn the user that the discussions are logged. This SHOULD be done by including a status code of "170" in the initial presence that the room sends to the new occupant:



Example 31. Service Sends New Occupant's Presence to New Occupant



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

    <status code='100'/>

    <status code='110'/>

    <status code='170'/>

    <status code='210'/>

  </x>

</presence>

      



7.1.15 Discussion History



After sending initial presence as shown above, a room MAY send discussion history to the new occupant. (The room MUST NOT send any discussion history before it finishes sending room presence as specified in the Presence Broadcast section of this document.) Whether such history is sent, and how many messages comprise the history, shall be determined by the chat service implementation or specific deployment.



Example 32. Delivery of Discussion History



<message

    from='darkcave@macbeth.shakespeare.lit/firstwitch'

    to='hecate@shakespeare.lit/broom'

    type='groupchat'>

  <body>Thrice the brinded cat hath mew'd.</body>

  <delay xmlns='urn:xmpp:delay'

     from='crone1@shakespeare.lit/desktop'

     stamp='2002-10-13T23:58:37Z'/>

</message>



<message

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='hecate@shakespeare.lit/broom'

    type='groupchat'>

  <body>Thrice and once the hedge-pig whined.</body>

  <delay xmlns='urn:xmpp:delay'

     from='wiccarocks@shakespeare.lit/laptop'

     stamp='2002-10-13T23:58:43Z'/>

</message>



<message

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hecate@shakespeare.lit/broom'

    type='groupchat'>

  <body>Harpier cries 'Tis time, 'tis time.</body>

  <delay xmlns='urn:xmpp:delay'

     from='hag66@shakespeare.lit/pda'

     stamp='2002-10-13T23:58:49Z'/>

</message>

      



Discussion history messages MUST be stamped with Delayed Delivery [10] information qualified by the 'urn:xmpp:delay' namespace to indicate that they are sent with delayed delivery and to specify the times at which they were originally sent. (Note: The 'urn:xmpp:delay' namespace defined in XEP-0203 supersedes the older 'jabber:x:delay' namespace defined in Delayed Delivery [11]; until the status of XEP-0091 is changed to Obsolete, implementations SHOULD include both datetime formats.) The 'from' attribute SHOULD be the full JID of the original sender in non-anonymous rooms, but MUST NOT be in semi-anonymous rooms (where the 'from' attribute SHOULD be set to the JID of the room itself). The service SHOULD send all discussion history messages before delivering any "live" messages sent after the user enters the room.

7.1.16 Managing Discussion History



A user MAY want to manage the amount of discussion history provided on entering a room (perhaps because the user is on a low-bandwidth connection or is using a small-footprint client). This MUST be accomplished by including a <history/> child in the initial presence stanza sent when joining the room. There are four allowable attributes for this element:



Table 7: History Management Attributes

Attribute 	Datatype 	Meaning

maxchars 	int 	Limit the total number of characters in the history to "X" (where the character count is the characters of the complete XML stanzas, not only their XML character data).

maxstanzas 	int 	Limit the total number of messages in the history to "X".

seconds 	int 	Send only the messages received in the last "X" seconds.

since 	dateTime 	Send only the messages received since the datetime specified (which MUST conform to the DateTime profile specified in XMPP Date and Time Profiles [12]).



The service MUST send the smallest amount of traffic that meets any combination of the above criteria, taking into account service-level and room-level defaults. The service MUST send complete message stanzas only (i.e., it MUST not literally truncate the history at a certain number of characters, but MUST send the largest number of complete stanzas that results in a number of characters less than or equal to the 'maxchars' value specified). If the client wishes to receive no history, it MUST set the 'maxchars' attribute to a value of "0" (zero).



The following examples illustrate the use of this protocol.



Example 33. User Requests Limit on Number of Messages in History



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'>

    <history maxstanzas='20'/>

  </x>

</presence>

      



Example 34. User Requests History in Last 3 Minutes



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'>

    <history seconds='180'/>

  </x>

</presence>

      



Example 35. User Requests All History Since the Beginning of the Unix Era



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'>

    <history since='1970-01-01T00:00Z'/>

  </x>

</presence>

      



Obviously the service SHOULD NOT return all messages sent in the room since the beginning of the Unix era, and SHOULD appropriately limit the amount of history sent to the user based on service or room defaults.



Example 36. User Requests No History



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'>

    <history maxchars='0'/>

  </x>

</presence>

      



7.2 Exiting a Room



In order to exit a multi-user chat room, an occupant sends a presence stanza of type "unavailable" to the <room@service/nick> it is currently using in the room.



Example 37. Occupant Exits a Room



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/thirdwitch'

    type='unavailable'/>

    



The service MUST then send presence stanzas of type "unavailable" from the departing occupant's room JID to the full JIDs of the departing occupant and of the remaining occupants:



Example 38. Service Sends Presence Related to Departure of Occupant



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='none'/>

    <status code='110'/>

  </x>

</presence>

<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='none'/>

  </x>

</presence>

<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='wiccarocks@shakespeare.lit/laptop'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='none'/>

  </x>

</presence>

    



Presence stanzas of type "unavailable" reflected by the room MUST contain extended presence information about roles and affiliations; the 'role' attribute SHOULD be set to a value of "none" to denote that the individual is no longer an occupant.



The occupant MAY include normal <status/> information in the unavailable presence stanzas; this enables the occupant to provide a custom exit message if desired:



Example 39. Custom Exit Message



<presence

    from='wiccarocks@shakespeare.lit/laptop'

    to='darkcave@macbeth.shakespeare.lit/oldhag'

    type='unavailable'>

  <status>gone where the goblins go</status>

</presence>

    



Normal presence stanza generation rules apply as defined in XMPP IM [13], so that if the user sends a general unavailable presence stanza, the user's server will broadcast that stanza to the <room@service/nick> to which the user's client has sent directed presence.



It is possible that a user may not be able to gracefully exit the room by sending unavailable presence directly to the room. If the user goes offline without sending unavailable presence, the user's server is responsible for sending unavailable presence on behalf of the user (in accordance with RFC 3921). If the user's server goes offline or connectivity is lost between the user's server and the MUC service to which the user is connected (e.g., in federated communications), the MUC service is responsible for monitoring error stanzas it receives in order to determine if the user has gone offline. If the MUC service determines that the user has gone offline, it must treat the user as if the user had itself sent unavailable presence.



Note: If the room is not persistent and this occupant is the last to exit, the service is responsible for destroying the room.

7.3 Changing Nickname



A common feature of multi-user chat rooms is the ability for an occupant to change his or her nickname within the room. In MUC this is done by sending updated presence information to the room, specifically by sending presence to a new room JID in the same room (changing only the resource identifier in the room JID).



Example 40. Occupant Changes Nickname



<presence

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit/oldhag'/>

    



The service then sends two presence stanzas to the full JID of each occupant (including the occupant who is changing his or her room nickname), one of type "unavailable" for the old nickname and one indicating availability for the new nickname.



The unavailable presence MUST contain the following as extended presence information in an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace:



    * The new nickname (in this case, nick='oldhag')

    * A status code of 303



This enables the recipients to correlate the old roomnick with the new roomnick.



Example 41. Service Updates Nick



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          nick='oldhag'

          role='participant'/>

    <status code='303'/>

  </x>

</presence>

<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='wiccarocks@shakespeare.lit/laptop'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          nick='oldhag'

          role='participant'/>

    <status code='303'/>

  </x>

</presence>

<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          nick='oldhag'

          role='participant'/>

    <status code='303'/>

    <status code='110'/>

  </x>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/oldhag'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

<presence

    from='darkcave@macbeth.shakespeare.lit/oldhag'

    to='wiccarocks@shakespeare.lit/laptop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

<presence

    from='darkcave@macbeth.shakespeare.lit/oldhag'

    to='hag66@shakespeare.lit/pda'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

    <status code='110'/>

  </x>

</presence>

    



If the user attempts to change his or her room nickname to a room nickname that is already in use by another user (or that is reserved by another user affiliated with the room, e.g., a member or owner), the service MUST deny the nickname change request and inform the user of the conflict; this is done by returning a presence stanza of type "error" specifying a <conflict/> error condition:



Example 42. Service Denies Nickname Change Because of Nick Conflict



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='409' type='cancel'>

    <conflict xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

    



However, if the bare JID (<node@domain.tld>) of the present occupant matches the bare JID of the user seeking to change his or her nickname, then the service MAY allow the nickname change. See the Nickname Conflict section of this document for details.



If the user attempts to change his or her room nickname but room nicknames are "locked down", the service MUST deny the nickname change request and return a presence stanza of type "error" specifying a <not-acceptable/> error condition:



Example 43. Service Denies Nickname Change Because Roomnicks Are Locked Down



<presence

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='406' type='cancel'>

    <not-acceptable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

    



The user SHOULD then discover its reserved nickname as specified in the Discovering Reserved Room Nickname section of this document.

7.4 Changing Availability Status



In multi-user chat systems such as IRC, one common use for changing one's room nickname is to indicate a change in one's availability (e.g., changing one's room nickname to "thirdwitch|away"). In Jabber, availability is of course noted by a change in presence (specifically the <show/> and <status/> elements), which can provide important context within a chatroom. An occupant changes availability status within the room by sending the updated presence to its <room@service/nick>.



Example 44. Occupant Changes Availability Status





<presence

    from='wiccarocks@shakespeare.lit/laptop'

    to='darkcave@macbeth.shakespeare.lit/oldhag'>

  <show>xa</show>

  <status>gone where the goblins go</status>

</presence>

    



The service then sends a presence stanza from the occupant changing his or her presence to the full JID of each occupant, including extended presence information about the occupant's role and full JID to those with privileges to view such information:



Example 45. Service Passes Along Changed Presence to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <show>xa</show>

  <status>gone where the goblins go</status>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='admin'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



7.5 Inviting Another User to a Room



It can be useful to invite another user to a room in which one is an occupant. To do this, a MUC client MUST send XML of the following form to the <room@service> itself (the reason is OPTIONAL and the message MUST be explicitly or implicitly of type "normal"):



Example 46. Occupant Sends an Invitation by Way of Room



<message

    from='crone1@shakespeare.lit/desktop'

    to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='hecate@shakespeare.lit'>

      <reason>

        Hey Hecate, this is the place for all good witches!

      </reason>

    </invite>

  </x>

</message>

    



The <room@service> itself MUST then add a 'from' address to the <invite/> element whose value is the bare JID (or, optionally, the room JID) of the invitor and send the invitation to the invitee captured in the 'to' address (the service SHOULD include a message body explaining the invitation or containing the reason, for the sake of older clients; in addition, the room SHOULD add the password if the room is password-protected):



Example 47. Room Sends Invitation to Invitee on Behalf of Invitor



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='hecate@shakespeare.lit'>

  <body>You have been invited to darkcave@macbeth by crone1@shakespeare.lit.</body>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite from='crone1@shakespeare.lit'>

      <reason>

        Hey Hecate, this is the place for all good witches!

      </reason>

    </invite>

    <password>cauldronburn</password>

  </x>

</message>

    



If the room is members-only, the service MAY also add the invitee to the member list. (Note: Invitation privileges in members-only rooms SHOULD be restricted to room admins; if a member without privileges to edit the member list attempts to invite another user, the service SHOULD return a <forbidden/> error to the occupant; for details, see the Modifying the Member List section of this document.)



If the invitor supplies a non-existent JID, the room SHOULD return an <item-not-found/> error to the invitor.



The invitee MAY choose to formally decline (as opposed to ignore) the invitation; and this is something that the sender may want to be informed about. In order to decline the invitation, the invitee MUST send a message of the following form to the <room@service> itself:



Example 48. Invitee Declines Invitation



<message

    from='hecate@shakespeare.lit/broom'

    to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <decline to='crone1@shakespeare.lit'>

      <reason>

        Sorry, I'm too busy right now.

      </reason>

    </decline>

  </x>

</message>

    



Example 49. Room Informs Invitor that Invitation Was Declined



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <decline from='hecate@shakespeare.lit'>

      <reason>

        Sorry, I'm too busy right now.

      </reason>

    </decline>

  </x>

</message>

    



It may be wondered why the invitee does not send the decline message directly to the invitor. The main reason is that certain implementations MAY choose to base invitations on room JIDs rather than bare JIDs (so that, for example, an occupant could invite someone from one room to another without knowing that person's bare JID). Thus the service MUST handle both the invites and declines.

7.6 Converting a One-to-One Chat Into a Conference



Sometimes it is desirable to convert a one-to-one chat into a multi-user conference. The process flow is shown in the following examples.



First, two users begin a one-to-one chat.



Example 50. A One-to-One Chat



<message

    from='crone1@shakespeare.lit/desktop'

    to='wiccarocks@shakespeare.lit/laptop'

    type='chat'>

  <body>Thrice the brinded cat hath mew'd.</body>

</message>



<message

    from='wiccarocks@shakespeare.lit/laptop'

    to='crone1@shakespeare.lit/desktop'

    type='chat'>

  <body>Thrice and once the hedge-pig whined.</body>

</message>

    



Now the first person decides to include a third person in the discussion, so she (or, more precisely, her client) does the following:



   1. Creates a new room

   2. Optionally sends history of the one-to-one chat to the room

   3. Sends an invitation to the second person and the third person, including a <continue/> flag.



Note: The new room SHOULD be non-anonymous, MAY be an instant room as specified in the Creating an Instant Room section of this document, and MAY have a unique room name received from the service as specified in the Requesting a Unique Room Name section of this document.



Example 51. Continuing the Discussion I: User Creates Room



<presence

    from='crone1@shakespeare.lit/desktop'

    to='darkcave@macbeth.shakespeare.lit/firstwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/firstwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='owner' role='moderator'/>

  </x>

</presence>

    



Example 52. Continuing the Discussion II: Owner Sends History to Room



<message

    from='crone1@shakespeare.lit/desktop'

    to='darkcave@macbeth.shakespeare.lit'

    type='groupchat'>

  <body>Thrice the brinded cat hath mew'd.</body>

  <delay xmlns='urn:xmpp:delay'

     from='crone1@shakespeare.lit/desktop'

     stamp='20040929T01:54:37Z'/>

</message>



<message

    from='crone1@shakespeare.lit/desktop'

    to='darkcave@macbeth.shakespeare.lit'

    type='groupchat'>

  <body>Thrice and once the hedge-pig whined.</body>

  <delay xmlns='urn:xmpp:delay'

     from='wiccarocks@shakespeare.lit/laptop'

     stamp='20040929T01:55:21Z'/>

</message>

    



Note: Use of the Delayed Delivery protocol enables the room creator to specify the datetime of each message from the one-to-one chat history (via the 'stamp' attribute), as well as the JID of the original sender of each message (via the 'from' attribute). The room creator SHOULD send the complete one-to-one chat history before inviting additional users to the room, and SHOULD also send as history any messages appearing in the one-to-one chat interface after joining the room and before the second person joins the room; if the one-to-one history is especially large, the sending client may want to send the history over a few seconds rather than all at once (to avoid triggering rate limits). The service SHOULD NOT add its own delay elements (as described in the Discussion History section of this document) to prior chat history messages received from the room owner.



Example 53. Continuing the Discussion III: Owner Sends Invitations, Including Continue Flag



<message

    from='crone1@shakespeare.lit/desktop'

    to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='wiccarocks@shakespeare.lit/laptop'>

      <reason>This coven needs both wiccarocks and hag66.</reason>

      <continue/>

    </invite>

    <invite to='hag66@shakespeare.lit'>

      <reason>This coven needs both wiccarocks and hag66.</reason>

      <continue/>

    </invite>

  </x>

</message>

    



Note: Since the invitor's client knows the full JID of the person with whom the invitor was having a one-to-one chat, it SHOULD include the full JID (rather than the bare JID) in the invitation.



The invitations are delivered to the invitees:



Example 54. Invitations Delivered



<message

    from='darkcave@macbeth.shakespeare.lit'>

    to='wiccarocks@shakespeare.lit/laptop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite from='crone1@shakespeare.lit'>

      <reason>This coven needs both wiccarocks and hag66.</reason>

      <continue/>

    </invite>

  </x>

</message>



<message

    from='darkcave@macbeth.shakespeare.lit'>

    to='hag66@shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite from='crone1@shakespeare.lit'>

      <reason>This coven needs both wiccarocks and hag66.</reason>

      <continue/>

    </invite>

  </x>

</message>

    



When the client being used by <wiccarocks@shakespeare.lit/laptop> receives the invitation, it SHOULD auto-join the room or prompt the user whether to join (subject to user preferences) and then seamlessly convert the existing one-to-one chat window into a multi-user conferencing window:



Example 55. Invitee Accepts Invitation, Joins Room, and Receives Presence and History



<presence

    from='wiccarocks@shakespeare.lit/laptop'

    to='darkcave@macbeth.shakespeare.lit/secondwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/firstwitch'

    to='wiccarocks@shakespeare.lit/laptop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='owner' role='moderator'/>

  </x>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='wiccarocks@shakespeare.lit/laptop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member' role='participant'/>

  </x>

</presence>



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='wiccarocks@shakespeare.lit/laptop'

    type='groupchat'>

  <body>Thrice the brinded cat hath mew'd.</body>

  <delay xmlns='urn:xmpp:delay'

     from='crone1@shakespeare.lit/desktop'

     stamp='20040929T01:54:37Z'/>

</message>



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='wiccarocks@shakespeare.lit/laptop'

    type='groupchat'>

  <body>Thrice and once the hedge-pig whined.</body>

  <delay xmlns='urn:xmpp:delay'

     from='wiccarocks@shakespeare.lit/laptop'

     stamp='20040929T01:55:21Z'/>

</message>

    



Note: The fact that the messages come from the <room@service> itself rather than <room@service/nick> is a clue to the receiving client that these messages are prior chat history, since any message from a room occupant will have a 'from' address equal to the sender's room JID.

7.7 Occupant Modification of the Room Subject



If allowed in accordance with room configuration, a mere occupant MAY be allowed to change the subject in a room. For details, see the Modifying the Room Subject section of this document.

7.8 Sending a Private Message



Since each occupant has a unique room JID, an occupant MAY send a "private message" to a selected occupant via the service by sending a message to the occupant's room JID. The message type SHOULD be "chat" and MUST NOT be "groupchat", but MAY be left unspecified (i.e., a normal message). This privilege SHOULD be allowed to any occupant (even a visitor in a moderated room).



Example 56. Occupant Sends Private Message



<message

    from='wiccarocks@shakespeare.lit/laptop'

    to='darkcave@macbeth.shakespeare.lit/firstwitch'

    type='chat'>

  <body>I'll give thee a wind.</body>

</message>

    



The service is responsible for changing the 'from' address to the sender's room JID and delivering the message to the intended recipient's full JID.



Example 57. Recipient Receives the Private Message



<message

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'

    type='chat'>

  <body>I'll give thee a wind.</body>

</message>

    



If the sender attempts to send a private message of type "groupchat" to a particular occupant, the service MUST refuse to deliver the message (since the recipient's client would expect in-room messages to be of type "groupchat") and return a <bad-request/> error to the sender:



Example 58. Occupant Attempts to Send a Message of Type "Groupchat" to a Particular Occupant



<message

    from='wiccarocks@shakespeare.lit/laptop'

    to='darkcave@macbeth.shakespeare.lit/firstwitch'

    type='groupchat'>

  <body>I'll give thee a wind.</body>

</message>



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='wiccarocks@shakespeare.lit/laptop'

    type='error'>

  <body>I'll give thee a wind.</body>

  <error code='400' type='modify'>

    <bad-request xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</message>

    



If the sender attempts to send a private message to a room JID that does not exist, the service MUST return an <item-not-found/> error to the sender.



If the sender is not an occupant of the room in which the intended recipient is visiting, the service MUST return a <not-acceptable/> error to the sender.

7.9 Sending a Message to All Occupants



An occupant sends a message to all other occupants in the room by sending a message of type "groupchat" to the <room@service> itself (a service MAY ignore or reject messages that do not have a type of "groupchat"). In a moderated room, this privilege is restricted to occupants with a role of participant or higher.



Example 59. Occupant Sends a Message to All Occupants



<message

    from='hag66@shakespeare.lit/pda'

    to='darkcave@macbeth.shakespeare.lit'

    type='groupchat'>

  <body>Harpier cries: 'tis time, 'tis time.</body>

</message>

    



If the sender has voice in the room (this is the default except in moderated rooms), the service MUST change the 'from' attribute to the sender's room JID and reflect the message out to the full JID of each occupant.



Example 60. Service Reflects Message to All Occupants



<message

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'

    type='groupchat'>

  <body>Harpier cries: 'tis time, 'tis time.</body>

</message>

<message

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='wiccarocks@shakespeare.lit/laptop'

    type='groupchat'>

  <body>Harpier cries: 'tis time, 'tis time.</body>

</message>

<message

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'

    type='groupchat'>

  <body>Harpier cries: 'tis time, 'tis time.</body>

</message>

    



If the sender is a visitor (i.e., does not have voice in a moderated room), the service MAY return a <forbidden/> error to the sender and MUST NOT reflect the message to all occupants. If the sender is not an occupant of the room, the service SHOULD return a <not-acceptable/> error to the sender and SHOULD NOT reflect the message to all occupants; the only exception to this rule is that an implementation MAY allow users with certain privileges (e.g., a room owner, room admin, or service-level admin) to send messages to the room even if those users are not occupants.

7.10 Registering with a Room



An implementation MAY allow an unaffiliated user (in a moderated room, normally a participant) to register with a room and thus become a member of the room (conversely, an implementation MAY restrict this privilege and allow only room admins to add new members). In particular, it is not possible to join a members-only room without being on the member list, so an entity may need to request membership in order to join such a room.



If allowed, this functionality SHOULD be implemented by enabling a user to send a request for registration requirements to the room qualified by the 'jabber:iq:register' namespace as described in In-Band Registration [14]:



Example 61. User Requests Registration Requirements



<iq from='hag66@shakespeare.lit/pda'

    id='reg1'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='jabber:iq:register'/>

</iq>

    



If the user requesting registration requirements is not allowed to register with the room (e.g., because that privilege has been restricted), the room MUST return a <not-allowed/> error to the user. If the user is already registered, the room MUST reply with an IQ stanza of type "result" that contains an empty <register/> element as described in XEP-0077. If the room does not exist, the service MUST return an <item-not-found/> error.



Otherwise, the room MUST then return a Data Form to the user (as described in Data Forms [15]). The information required to register MAY vary by implementation or deployment and is not fully specified in this document (e.g., the fields registered by this document for the 'http://jabber.org/protocol/muc#register' FORM_TYPE may be supplemented in the future via the mechanisms described in the Field Standardization section of this document). The following can be taken as a fairly typical example:



Example 62. Service Returns Registration Form



<iq from='darkcave@macbeth.shakespeare.lit'

    id='reg1'

    to='hag66@shakespeare.lit/pda'

    type='result'>

  <query xmlns='jabber:iq:register'>

    <instructions>

      To register on the web, visit http://shakespeare.lit/

    </instructions>

    <x xmlns='jabber:x:data' type='form'>

      <title>Dark Cave Registration</title>

      <instructions>

        Please provide the following information

        to register with this room.

      </instructions>

      <field

          type='hidden'

          var='FORM_TYPE'>

        <value>http://jabber.org/protocol/muc#register</value>

      </field>

      <field

          label='First Name'

          type='text-single'

          var='muc#register_first'>

        <required/>

      </field>

      <field

          label='Last Name'

          type='text-single'

          var='muc#register_last'>

        <required/>

      </field>

      <field

          label='Desired Nickname'

          type='text-single'

          var='muc#register_roomnick'>

        <required/>

      </field>

      <field

          label='Your URL'

          type='text-single'

          var='muc#register_url'/>

      <field

          label='Email Address'

          type='text-single'

          var='muc#register_email'/>

      <field

          label='FAQ Entry'

          type='text-multi'

          var='muc#register_faqentry'/>

    </x>

  </query>

</iq>

    



The user SHOULD then submit the form:



Example 63. User Submits Registration Form



<iq from='hag66@shakespeare.lit/pda'

    id='reg2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='jabber:iq:register'>

    <x xmlns='jabber:x:data' type='submit'>

      <field var='FORM_TYPE'>

        <value>http://jabber.org/protocol/muc#register</value>

      </field>

      <field var='muc#register_first'>

        <value>Brunhilde</value>

      </field>

      <field var='muc#register_last'>

        <value>Entwhistle-Throckmorton</value>

      </field>

      <field var='muc#register_roomnick'>

        <value>thirdwitch</value>

      </field>

      <field var='muc#register_url'>

        <value>http://witchesonline/~hag66/</value>

      </field>

      <field var='muc#register_email'>

        <value>hag66@witchesonline</value>

      </field>

      <field var='muc#register_faqentry'>

        <value>Just another witch.</value>

      </field>

    </x>

  </query>

</iq>

    



If the desired room nickname is already reserved for that room, the room MUST return a <conflict/> error to the user:



Example 64. Room Returns Conflict Error to User



<iq from='darkcave@macbeth.shakespeare.lit'

    id='reg2'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='409' type='cancel'>

    <conflict xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



If the room or service does not support registration, it MUST return a <service-unavailable/> error to the user:



Example 65. Room Returns Service Unavailable Error to User



<iq from='darkcave@macbeth.shakespeare.lit'

    id='reg2'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='503' type='cancel'>

    <service-unavailable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



If the user did not include a valid data form, the room MUST return a <bad-request/> error to the user:



Example 66. Room Returns Service Bad Request Error to User



<iq from='darkcave@macbeth.shakespeare.lit'

    id='reg2'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='400' type='modify'>

    <bad-request xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



Otherwise, the room MUST inform the user that the registration request was successfully received:



Example 67. Room Informs User that Registration Request Has Been Processed



<iq from='darkcave@macbeth.shakespeare.lit'

    id='reg2'

    to='hag66@shakespeare.lit/pda'

    type='result'/>

    



After the user submits the form, the service MAY request that the submission be approved by a room admin/owner (see the Approving Registration Requests section of this document) or MAY immediately add the user to the member list by changing the user's affiliation from "none" to "member". If the service changes the user's affiliation and the user is in the room, it MUST send updated presence from this individual to all occupants, indicating the change in affiliation by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "member".



Example 68. Service Sends Notice of Membership to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

.

.

.

    



If a user has registered with a room, the room MAY choose to restrict the user to use of the registered nickname only in that room. If it does so, it SHOULD return a <not-acceptable/> error to the user if the user attempts to join the room with a roomnick other than the user's registered roomnick (this enables a room to "lock down" roomnicks for consistent identification of occupants).

7.11 Discovering Reserved Room Nickname



A user MAY have a reserved room nickname, for example through explicit room registration, database integration, or nickname "lockdown". A user SHOULD discover his or her reserved nickname before attempting to enter the room. This is done by sending a Service Discovery information request to the room JID while specifying a well-known Service Discovery node of "x-roomuser-item".



Example 69. User Requests Reserved Nickname



<iq from='hag66@shakespeare.lit/pda'

    id='getnick1'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/disco#info'

         node='x-roomuser-item'/>

</iq>

    



It is OPTIONAL for a multi-user chat service to support the foregoing service discovery node. If the room or service does not support the foregoing service discovery node, it MUST return a <feature-not-implemented/> error to the user. If it does and the user has a registered nickname, it MUST return the nickname to the user as the value of the 'name' attribute of a Service Discovery <identity/> element (for which the category/type SHOULD be "conference/text"):



Example 70. Room Returns Nickname



<iq from='darkcave@macbeth.shakespeare.lit'

    id='getnick1'

    to='hag66@shakespeare.lit/pda'

    type='result'>

  <query xmlns='http://jabber.org/protocol/disco#info'

         node='x-roomuser-item'>

    <identity

        category='conference'

        name='thirdwitch'

        type='text'/>

  </query>

</iq>

    



If the user does not have a registered nickname, the room MUST return a service discovery <query/> element that is empty (in accordance with XEP-0030).



Even if a user has registered one room nickname, the service SHOULD allow the user to specify a different nickname on entering the room (e.g., in order to join from different client resources), although the service MAY choose to "lock down" nicknames and therefore deny entry to the user, including a <not-acceptable/> error. The service MUST NOT return an error to the user if his or her client sends the foregoing request after having already joined the room, but instead SHOULD reply as described above.



If another user attempts to join the room with a nickname reserved by the first user, the service MUST deny entry to the second user and return a <conflict/> error as previously described.

7.12 Requesting Voice



It is not possible for a visitor to speak (i.e., send a message to all occupants) in a moderated room. To request voice, a visitor SHOULD send a <message/> stanza containing a data form to the room itself, where data form contains only a 'muc#role' field with a value of "participant".



Example 71. Occupant Requests Voice



<message from='hag66@shakespeare.lit/pda'

         to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='jabber:x:data' type='submit'>

    <field var='FORM_TYPE'>

      <value>http://jabber.org/protocol/muc#request</value>

    </field>

    <field var='muc#role'

           type='text-single'

           label='Requested role'>

      <value>participant</value>

    </field>

  </x>

</message>

    



The service then SHOULD forward the request to the room moderator(s) as described in the Approving Voice Requests section of this document.

8. Moderator Use Cases



A moderator has privileges to perform certain actions within the room (e.g., to change the roles of some occupants) but does not have rights to change persistent information about affiliations (which may be changed only by an admin or owner) or defining information about the room. Exactly which actions may be performed by a moderator is subject to configuration. However, for the purposes of the MUC framework, moderators are stipulated to have privileges to perform the following actions:



   1. discover an occupant's full JID in a semi-anonymous room (occurs by default as shown above)

   2. modify the subject

   3. kick a participant or visitor from the room

   4. grant or revoke voice in a moderated room

   5. modify the list of occupants who have voice in a moderated room



These features shall be implemented with a request/response exchange using <iq/> elements that contain children qualified by the 'http://jabber.org/protocol/muc#admin' namespace. The examples below illustrate the protocol interactions to implement the desired functionality. (Except where explicitly noted below, any of the following administrative requests MUST be denied if the <user@host> of the 'from' address of the request does not match the bare JID portion of one of the moderators; in this case, the service MUST return a <forbidden/> error.)

8.1 Modifying the Room Subject



A common feature of multi-user chat rooms is the ability to change the subject within the room. By default, only users with a role of "moderator" SHOULD be allowed to change the subject in a room (although this SHOULD be configurable, with the result that a mere participant or even visitor may be allowed to change the subject if desired). The subject is changed by sending a message of type "groupchat" to the <room@service>, containing no body but a <subject/> that specifies the new subject:



Example 72. Moderator Changes Subject



<message

    from='wiccarocks@shakespeare.lit/laptop'

    to='darkcave@macbeth.shakespeare.lit'

    type='groupchat'>

  <subject>Fire Burn and Cauldron Bubble!</subject>

</message>

    



If a MUC service receives such a message, it MUST reflect the message to all other occupants with a 'from' address equal to the room JID that corresponds to the sender of the subject change:



Example 73. Service Informs All Occupants of Subject Change



<message

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'

    type='groupchat'>

  <subject>Fire Burn and Cauldron Bubble!</subject>

</message>

.

.

.

    



In addition, the room SHOULD include the last subject change in the discussion history sent when a new occupant joins the room.



A MUC client that receives such a message MAY choose to display an in-room message, such as the following:



Example 74. Client Displays Room Subject Change Message



* secondwitch has changed the subject to: Fire Burn and Cauldron Bubble!

    



If someone without appropriate privileges attempts to change the room subject, the service MUST return a message of type "error" specifying a <forbidden/> error condition:



Example 75. Service Returns Error Related to Unauthorized Subject Change



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <subject>Fire Burn and Cauldron Bubble!</subject>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</message>

    



8.2 Kicking an Occupant



A moderator has permissions kick certain kinds of occupants from a room (which occupants are "kickable" depends on service provisioning, room configuration, and the moderator's affiliation -- see below). The kick is normally performed based on the occupant's room nickname (though it MAY be based on the full JID) and is completed by setting the role of a participant or visitor to a value of "none".



Example 76. Moderator Kicks Occupant



<iq from='fluellen@shakespeare.lit/pda'

    id='kick1'

    to='harfleur@henryv.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='pistol' role='none'>

      <reason>Avaunt, you cullion!</reason>

    </item>

  </query>

</iq>

    



The service MUST remove the kicked occupant by sending a presence stanza of type "unavailable" to each kicked occupant, including status code 307 in the extended presence information, optionally along with the reason (if provided) and the bare JID of the user who initiated the kick.



Example 77. Service Removes Kicked Occupant



<presence

    from='harfleur@henryv.shakespeare.lit/pistol'

    to='pistol@shakespeare.lit/harfleur'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'>

      <actor jid='fluellen@shakespeare.lit'/>

      <reason>Avaunt, you cullion!</reason>

    </item>

    <status code='307'/>

  </x>

</presence>

    



The inclusion of the status code assists clients in presenting their own notification messages (e.g., information appropriate to the user's locality). The optional inclusion of the reason and actor enable the kicked user to understand why he or she was kicked, and by whom if the kicked occupant would like to discuss the matter. [16]



After removing the kicked occupant(s), the service MUST then inform the moderator of success:



Example 78. Service Informs Moderator of Success



<iq from='harfleur@henryv.shakespeare.lit'

    id='kick1'

    to='fluellen@shakespeare.lit/pda'

    type='result'/>

    



After informing the moderator, the service MUST then inform all of the remaining occupants that the kicked occupant is no longer in the room by sending presence stanzas of type "unavailable" from the individual's roomnick (<room@service/nick>) to all the remaining occupants (just as it does when occupants exit the room of their own volition), including the status code and optionally the reason and actor.



Example 79. Service Informs Remaining Occupants



<presence

    from='harfleur@henryv.shakespeare.lit/pistol'

    to='gower@shakespeare.lit/cell'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'/>

    <status code='307'/>

  </x>

</presence>

.

.

.

    



A user cannot be kicked by a moderator with a lower affiliation. Therefore, if a moderator who is a participant attempts to kick an admin or a moderator who is a participant or admin attempts to kick an owner, the service MUST deny the request and return a <not-allowed/> error to the sender:



Example 80. Service Returns Error on Attempt to Kick User With Higher Affiliation



<iq from='darkcave@macbeth.shakespeare.lit'

    id='kicktest'

    to='wiccarocks@shakespeare.lit/laptop'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='firstwitch' role='none'>

      <reason>Be gone!</reason>

    </item>

  </query>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



If a moderator attempts to kick himself, the service MAY deny the request and return a <conflict/> error to the sender. (Although the act of kicking oneself may seem odd, it is common in IRC as a way of apologizing for one's actions in the room.)

8.3 Granting Voice to a Visitor



In a moderated room, a moderator may want to manage who does and does not have "voice" in the room (i.e., the ability to send messages to all occupants). Voice is granted based on the visitor's room nickname, which the service will convert into the visitor's full JID internally. The moderator grants voice to a visitor by changing the visitor's role to "participant" (the <reason/> element is optional):



Example 81. Moderator Grants Voice to a Visitor



<iq from='crone1@shakespeare.lit/desktop'

    id='voice1'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='thirdwitch'

          role='participant'>

      <reason>A worthy witch indeed!</reason>

    </item>

  </query>

</iq>

    



The service MUST then inform the moderator of success:



Example 82. Service Informs Moderator of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='voice1'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence from this individual's <room@service/nick> to all occupants, indicating the addition of voice privileges by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'role' attribute set to a value of "participant".



Example 83. Service Sends Notice of Voice to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          nick='thirdwitch'

          role='participant'>

      <reason>A worthy witch indeed!</reason>

    </item>

  </x>

</presence>

.

.

.

    



8.4 Revoking Voice from a Participant



In a moderated room, a moderator may want to revoke a participant's privileges to speak. The moderator can revoke voice from a participant by changing the participant's role to "visitor":



Example 84. Moderator Revokes Voice from a Participant



<iq from='crone1@shakespeare.lit/desktop'

    id='voice2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='thirdwitch'

          role='visitor'/>

  </query>

</iq>

    



The service MUST then inform the moderator of success:



Example 85. Service Informs Moderator of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='voice2'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence from this individual to all occupants, indicating the removal of voice privileges by sending a presence element that contains an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'role' attribute set to a value of "visitor".



Example 86. Service Notes Loss of Voice



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='visitor'/>

  </x>

</presence>

.

.

.

    



A moderator MUST NOT be able to revoke voice from a user whose affiliation is at or above the moderator's level. In addition, a service MUST NOT allow the voice privileges of an admin or owner to be removed by anyone. If a moderator attempts to revoke voice privileges from such a user, the service MUST deny the request and return a <not-allowed/> error to the sender along with the offending item(s):



Example 87. Service Returns Error on Attempt to Revoke Voice from an Admin, Owner, or User with a Higher Affiliation



<iq from='darkcave@macbeth.shakespeare.lit'

    id='voicetest'

    to='crone1@shakespeare.lit/desktop'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='secondwitch' role='visitor'/>

  </query>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



8.5 Modifying the Voice List



A moderator in a moderated room may want to modify the voice list. To do so, the moderator first requests the voice list by querying the room for all occupants with a role of 'participant'.



Example 88. Moderator Requests Voice List



<iq from='bard@shakespeare.lit/globe'

    id='voice3'

    to='goodfolk@chat.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item role='participant'/>

  </query>

</iq>

    



The service MUST then return the voice list to the moderator; each item MUST include the 'nick' and 'role' attributes and SHOULD include the 'affiliation' and 'jid' attributes:



Example 89. Service Sends Voice List to Moderator



<iq from='goodfolk@chat.shakespeare.lit'

    id='voice3'

    to='bard@shakespeare.lit/globe'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='none'

          jid='polonius@hamlet/castle'

          nick='Polo'

          role='participant'/>

    <item affiliation='none'

          jid='horatio@hamlet/castle'

          nick='horotoro'

          role='participant'/>

    <item affiliation='member'

          jid='hecate@shakespeare.lit/broom'

          nick='Hecate'

          role='participant'/>

  </query>

</iq>

    



The moderator MAY then modify the voice list. In order to do so, the moderator MUST send the changed items (i.e., only the "delta") back to the service; each item MUST include the 'nick' attribute and 'role' attribute (normally set to a value of "participant" or "visitor") but SHOULD NOT include the 'jid' attribute and MUST NOT include the 'affiliation' attribute (which is used to manage affiliations such as owner rather than the participant role):



Example 90. Moderator Sends Modified Voice List to Service



<iq from='bard@shakespeare.lit/globe'

    id='voice4'

    to='goodfolk@chat.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='Hecate'

          role='visitor'/>

    <item nick='rosencrantz'

          role='participant'>

      <reason>A worthy fellow.</reason>

    </item>

    <item nick='guildenstern'

          role='participant'>

      <reason>A worthy fellow.</reason>

    </item>

  </query>

</iq>

    



The service MUST then inform the moderator of success:



Example 91. Service Informs Moderator of Success



<iq from='goodfolk@chat.shakespeare.lit'

    id='voice1'

    to='bard@shakespeare.lit/globe'

    type='result'/>

    



The service MUST then send updated presence for any affected individuals to all occupants, indicating the change in voice privileges by sending the appropriate extended presence stanzas as described in the foregoing use cases.



As noted, voice privileges cannot be revoked from a room owner or room admin, nor from any user with a higher affiliation than the moderator making the request. If a room admin attempts to revoke voice privileges from such a user by modifying the voice list, the service MUST deny the request and return a <not-allowed/> error to the sender:



Example 92. Service Returns Error on Attempt to Revoke Voice from an Admin, Owner, or User with a Higher Affiliation



<iq from='goodfolk@chat.shakespeare.lit'

    id='voicetest'

    to='bard@shakespeare.lit/globe'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item jid='hecate@shakespeare.lit'

          nick='Hecate'

          role='visitor'/>

  </query>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



8.6 Approving Voice Requests



As noted in the Requesting Voice section of this document, when a service receives a request for voice from an occupant it SHOULD forward that request to the room moderator(s). To do so, the service SHOULD send a <message/> stanza to the room moderator(s), where the <message/> stanza contains a data form asking for approval or denial of the request, as shown below.



Example 93. Voice Request Approval Form



<message from='darkcave@macbeth.shakespeare.lit'

         id='approve'

         to='crone1@shakespeare.lit/pda'>

  <x xmlns='jabber:x:data' type='form'>

    <title>Voice request</title>

    <instructions>

      To approve this request for voice, select 

      the &quot;Grant voice to this person?&quot;

      checkbox and click OK. To skip this request, 

      click the cancel button.

    </instructions>

    <field var='FORM_TYPE' type='hidden'>

        <value>http://jabber.org/protocol/muc#request</value>

    </field>

    <field var='muc#role'

           type='text-single'

           label='Requested role'>

      <value>participant</value>

    </field>

    <field var='muc#jid'

           type='text-single'

           label='User ID'>

      <value>hag66@shakespeare.lit/pda</value>

    </field>

    <field var='muc#roomnick'

           type='text-single'

           label='Room Nickname'>

      <value>thirdwitch</value>

    </field>

    <field var='muc#request_allow'

           type='boolean'

           label='Grant voice to this person?'>

      <value>false</value>

    </field>

  </x>

</message>

    



In order to approve the request, a moderator shall submit the form:



Example 94. Voice Request Approval Submission



<message from='crone1@shakespeare.lit/pda'

         id='approve'

         to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='jabber:x:data' type='submit'>

    <field var='FORM_TYPE' type='hidden'>

        <value>http://jabber.org/protocol/muc#request</value>

    </field>

    <field var='muc#role'>

      <value>participant</value>

    </field>

    <field var='muc#jid'>

      <value>hag66@shakespeare.lit/pda</value>

    </field>

    <field var='muc#roomnick'>

      <value>thirdwitch</value>

    </field>

    <field var='muc#request_allow'>

      <value>true</value>

    </field>

  </x>

</message>

    



If a moderator approves the voice request, the service shall grant voice to the occupant and send a presence update as described in the Granting Voice to a Visitor section of this document.

9. Admin Use Cases



A room administrator has privileges to modify persistent information about user affiliations (e.g., by banning users) and to grant and revoke moderator privileges, but does not have rights to change the defining features of the room, which are the sole province of the room owner(s). Exactly which actions may be performed by a room admin will be subject to configuration. However, for the purposes of the MUC framework, room admins are stipulated to at a minimum have privileges to perform the following actions:



   1. ban a user from the room

   2. modify the list of users who are banned from the room

   3. grant or revoke membership

   4. modify the member list

   5. grant or revoke moderator privileges

   6. modify the list of moderators



These features shall be implemented with a request/response exchange using <iq/> elements that contain children qualified by the 'http://jabber.org/protocol/muc#admin' namespace. The examples below illustrate the protocol interactions that implement the desired functionality. (Except where explicitly noted below, any of the following administrative requests MUST be denied if the <user@host> of the 'from' address of the request does not match the bare JID of one of the room admins; in this case, the service MUST return a <forbidden/> error.)

9.1 Banning a User



An admin or owner can ban one or more users from a room. The ban MUST be performed based on the occupant's bare JID. In order to ban a user, an admin MUST change the user's affiliation to "outcast".



Example 95. Admin Bans User



<iq from='kinghenryv@shakespeare.lit/throne'

    id='ban1'

    to='southampton@henryv.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='outcast'

          jid='earlofcambridge@shakespeare.lit'>

      <reason>Treason</reason>

    </item>

  </query>

</iq>

    



The service MUST add that bare JID to the ban list, SHOULD remove the outcast's nickname from the list of registered nicknames, and MUST inform the admin or owner of success:



Example 96. Service Informs Admin or Owner of Success



<iq from='southampton@henryv.shakespeare.lit'

    id='ban1'

    to='kinghenryv@shakespeare.lit/throne'

    type='result'/>

    



The service MUST also remove any banned users who are in the room by sending a presence stanza of type "unavailable" to each banned occupant, including status code 301 in the extended presence information, optionally along with the reason (if provided) and the bare JID of the user who initiated the ban.



Example 97. Service Removes Banned User



<presence

    from='southampton@henryv.shakespeare.lit/cambridge'

    to='earlofcambridge@shakespeare.lit/stabber'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='outcast' role='none'>

      <actor jid='kinghenryv@shakespeare.lit'/>

      <reason>Treason</reason>

    </item>

    <status code='301'/>

  </x>

</presence>

    



The inclusion of the status code assists clients in presenting their own notification messages (e.g., information appropriate to the user's locality). The optional inclusion of the reason and actor enable the banned user to understand why he or she was banned, and by whom if the banned user would like to discuss the matter.



The service MUST then inform all of the remaining occupants that the banned user is no longer in the room by sending presence stanzas of type "unavailable" from the banned user to all remaining occupants (just as it does when occupants exit the room of their own volition), including the status code and optionally the reason and actor:



Example 98. Service Informs Remaining Occupants



<presence

    type='unavailable'

    from='southampton@henryv.shakespeare.lit/cambridge'

    to='exeter@shakespeare.lit/pda'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='outcast'

          jid='earlofcambridge@shakespeare.lit/stabber'

          role='none'/>

    <status code='301'/>

  </x>

</presence>

.

.

.

    



As with Kicking an Occupant, a user cannot be banned by an admin with a lower affiliation. Therefore, if an admin attempts to ban an owner, the service MUST deny the request and return a <not-allowed/> error to the sender:



Example 99. Service Returns Error on Attempt to Ban User With Higher Affiliation



<iq from='kinghenryv@shakespeare.lit/throne'

    id='ban1'

    to='southampton@henryv.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='outcast'

          jid='earlofcambridge@shakespeare.lit'>

      <reason>Treason</reason>

    </item>

  </query>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



If an admin or owner attempts to ban himself, the service MUST deny the request and return a <conflict/> error to the sender. (Note: This is different from the recommended service behavior on kicking oneself, which a service may allow.)

9.2 Modifying the Ban List



A room admin may want to modify the ban list. Note: The ban list is always based on a user's bare JID, although a nick (perhaps the last room nickname associated with that JID) MAY be included for convenience. To modify the list of banned JIDs, the admin first requests the ban list by querying the room for all users with an affiliation of 'outcast'.



Example 100. Admin Requests Ban List



<iq from='kinghenryv@shakespeare.lit/throne'

    id='ban2'

    to='southampton@henryv.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='outcast'/>

  </query>

</iq>

    



The service MUST then return the list of banned users to the admin; each item MUST include the 'affiliation' and 'jid' attributes but SHOULD NOT include the 'nick' and 'role' attributes:



Example 101. Service Sends Ban List to Admin



<iq from='southampton@henryv.shakespeare.lit'

    id='ban2'

    to='kinghenryv@shakespeare.lit/throne'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='outcast'

          jid='earlofcambridge@shakespeare.lit'>

      <reason>Treason</reason>

    </item>

  </query>

</iq>

    



The admin MAY then modify the ban list. In order to do so, the admin MUST send the changed items (i.e., only the "delta") back to the service; each item MUST include the 'affiliation' attribute (normally set to a value of "outcast" to ban or "none" to remove ban) and 'jid' attribute but SHOULD NOT include the 'nick' attribute and MUST NOT include the 'role' attribute (which is used to manage roles such as participant rather than the outcast affiliation); in addition, the reason and actor elements are OPTIONAL:



Example 102. Admin Sends Modified Ban List to Service



<iq from='kinghenryv@shakespeare.lit/throne'

    id='ban3'

    to='southampton@henryv.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='outcast'

          jid='earlofcambridge@shakespeare.lit'>

      <reason>Treason</reason>

    </item>

    <item affiliation='outcast'>

          jid='lordscroop@shakespeare.lit'>

      <reason>Treason</reason>

    </item>

    <item affiliation='outcast'

          jid='sirthomasgrey@shakespeare.lit'>

      <reason>Treason</reason>

    </item>

  </query>

</iq>

    



After updating the ban list, the service MUST inform the admin of success:



Example 103. Service Informs Admin of Success



<iq from='southampton@henryv.shakespeare.lit'

    id='ban3'

    to='kinghenryv@shakespeare.lit/throne'

    type='result'/>

    



The service MUST then remove the affected occupants (if they are in the room) and send updated presence (including the appropriate status code) from them to all the remaining occupants as described in the "Banning a User" use case. (The service SHOULD also remove each banned user's reserved nickname from the list of reserved roomnicks, if appropriate.)



When an entity is banned from a room, an implementation SHOULD match JIDs in the following order (these matching rules are the same as those defined for privacy lists in RFC 3921):



   1. <user@domain/resource> (only that resource matches)

   2. <user@domain> (any resource matches)

   3. <domain/resource> (only that resource matches)

   4. <domain> (the domain itself matches, as does any user@domain, domain/resource, or address containing a subdomain)



Some administrators may wish to ban all users associated with a specific domain from all rooms hosted by a MUC service. Such functionality is a service-level feature and is therefore out of scope for this document (but see Service Administration [17]).

9.3 Granting Membership



An admin can grant membership to a user; this is done by changing the user's affiliation to "member" (normally based on nick if the user is in the room, or on bare JID if not; in either case, if the nick is provided, that nick becomes the user's default nick in the room if that functionality is supported by the implementation):



Example 104. Admin Grants Membership



<iq from='crone1@shakespeare.lit/desktop'

    id='member1'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit'/>

  </query>

</iq>

    



The service MUST add the user to the member list and then inform the admin of success:



Example 105. Service Informs Admin of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='member1'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



If the user is in the room, the service MUST then send updated presence from this individual to all occupants, indicating the granting of membership by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "member".



Example 106. Service Sends Notice of Membership to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

.

.

.

    



9.4 Revoking Membership



An admin may want to revoke a user's membership; this is done by changing the user's affiliation to "none":



Example 107. Admin Revokes Membership



<iq from='crone1@shakespeare.lit/desktop'

    id='member2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='none'

          jid='hag66@shakespeare.lit'/>

  </query>

</iq>

    



The service MUST remove the user from the member list and then inform the moderator of success:



Example 108. Service Informs Moderator of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='member2'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence from this individual to all occupants, indicating the loss of membership by sending a presence element that contains an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "none".



Example 109. Service Notes Loss of Membership



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

.

.

.

    



If the room is members-only, the service MUST remove the user from the room, including a status code of 321 to indicate that the user was removed because of an affiliation change, and inform all remaining occupants:



Example 110. Service Removes Non-Member



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'>

      <actor jid='bard@shakespeare.lit'/>

    </item>

    <status code='321'/>

  </x>

</presence>



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'/>

    <status code='321'/>

  </x>

</presence>

.

.

.

    



9.5 Modifying the Member List



In the context of a members-only room, the member list is essentially a "whitelist" of people who are allowed to enter the room. Anyone who is not a member is effectively banned from entering the room, even if their affiliation is not "outcast".



In the context of an open room, the member list is simply a list of users (bare JID and reserved nick) who are registered with the room. Such users may appear in a room roster, have their room nickname reserved, be returned in search results or FAQ queries, and the like.



It is RECOMMENDED that only room admins have the privilege to modify the member list in members-only rooms. To do so, the admin first requests the member list by querying the room for all users with an affiliation of "member":



Example 111. Admin Requests Member List



<iq from='crone1@shakespeare.lit/desktop'

    id='member3'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='member'/>

  </query>

</iq>

    



(A service SHOULD also return the member list to any occupant in a members-only room; i.e., it SHOULD NOT generate a <forbidden/> error when a member in the room requests the member list. This functionality may assist clients in showing all the existing members even if some of them are not in the room, e.g. to help a member determine if another user should be invited.)



The service MUST then return the full member list to the admin qualified by the 'http://jabber.org/protocol/muc#admin' namespace; each item MUST include the 'affiliation' and 'jid' attributes and MAY include the 'nick' and 'role' attributes for each members that is currently an occupant.



Example 112. Service Sends Member List to Admin



<iq from='darkcave@macbeth.shakespeare.lit'

    id='member3'

    to='crone1@shakespeare.lit/desktop'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit'

          nick='thirdwitch'

          role='participant'/>

  </query>

</iq>

    



The admin MAY then modify the member list. In order to do so, the admin MUST send the changed items (i.e., only the "delta") to the service; each item MUST include the 'affiliation' attribute (normally set to a value of "member" or "none") and 'jid' attribute but SHOULD NOT include the 'nick' attribute and MUST NOT include the 'role' attribute (which is used to manage roles such as participant rather than the member affiliation):



Example 113. Admin Sends Modified Member List to Service



<iq from='crone1@shakespeare.lit/desktop'

    id='member4'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='none'

          jid='hag66@shakespeare.lit'/>

    <item affiliation='member'

          jid='hecate@shakespeare.lit'/>

  </query>

</iq>

    



The service MUST modify the member list and then inform the moderator of success:



Example 114. Service Informs Moderator of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='member4'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST change the affiliation of any affected user. If the user has been removed from the member list, the service MUST change the user's affiliation from "member" to "none". If the user has been added to the member list, the service MUST change the user's affiliation to "member".



If a removed member is currently in a members-only room, the service SHOULD kick the occupant by changing the removed member's role to "none" and send appropriate presence to the removed member as previously described. No matter whether the removed member was in or out of a members-only room, the service MUST subsequently refuse entry to the user.



For all room types, the service MUST send updated presence from this individual to all occupants, indicating the change in affiliation by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "none".



Example 115. Service Sends Notice of Loss of Membership to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

.

.

.

    



In addition, the service SHOULD send an invitation to any user who has been added to the member list of a members-only room if the user is not currently affiliated with the room, for example as an admin or owner (such a user would by definition not be in the room; note also that this example includes a password but not a reason -- both child elements are OPTIONAL):



Example 116. Room Sends Invitation to New Member



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='hecate@shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite from='bard@shakespeare.lit'/>

    <password>cauldronburn</password>

  </x>

</message>

    



While only admins and owners SHOULD be allowed to modify the member list, an implementation MAY provide a configuration option that opens invitation privileges to any member of a members-only room. In such a situation, any invitation sent SHOULD automatically trigger the addition of the invitee to the member list. However, if invitation privileges are restricted to admins and a mere member attempts to a send an invitation, the service MUST deny the invitation request and return a <forbidden/> error to the sender:



Example 117. Service Returns Error on Attempt by Mere Member to Invite Others to a Members-Only Room



<message

    from='darkcave@macbeth.shakespeare.lit'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='hecate@shakespeare.lit'>

      <reason>

        Hey Hecate, this is the place for all good witches!

      </reason>

    </invite>

  </x>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</message>

    



Invitations sent through an open room MUST NOT trigger the addition of the invitee to the member list.



If a user is added to the member list of an open room and the user is in the room, the service MUST send updated presence from this individual to all occupants, indicating the change in affiliation by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "member".



Example 118. Service Sends Notice of Membership to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/hecate'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hecate@shakespeare.lit/broom'

          role='participant'/>

  </x>

</presence>

.

.

.

    



9.6 Granting Moderator Privileges



An admin may want to grant moderator privileges to a participant or visitor; this is done by changing the user's role to "moderator":



Example 119. Admin Grants Moderator Privileges



<iq from='crone1@shakespeare.lit/desktop'

    id='mod1'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='thirdwitch'

          role='moderator'/>

  </query>

</iq>

    



The service MUST add the user to the moderator list and then inform the admin of success:



Example 120. Service Informs Admin of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='mod1'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence from this individual to all occupants, indicating the addition of moderator privileges by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'role' attribute set to a value of "moderator".



Example 121. Service Sends Notice of Moderator Privileges to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



9.7 Revoking Moderator Privileges



An admin may want to revoke a user's moderator privileges. An admin MAY revoke moderator privileges only from a user whose affiliation is "member" or "none" (i.e., not from an owner or admin). The privilege is revoked by changing the user's role to "participant":



Example 122. Admin Revokes Moderator Privileges



<iq from='crone1@shakespeare.lit/desktop'

    id='mod2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='thirdwitch'

          role='participant'/>

  </query>

</iq>

    



The service MUST remove the user from the moderator list and then inform the admin of success:



Example 123. Service Informs Admin of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='mod2'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence from this individual to all occupants, indicating the removal of moderator privileges by sending a presence element that contains an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'role' attribute set to a value of "participant".



Example 124. Service Notes Loss of Moderator Privileges



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          role='participant'/>

  </x>

</presence>

.

.

.

    



As noted, an admin MUST NOT be allowed to revoke moderator privileges from a user whose affiliation is "owner" or "admin". If an admin attempts to revoke moderator privileges from such a user, the service MUST deny the request and return a <not-allowed/> error to the sender:



Example 125. Service Returns Error on Attempt to Revoke Moderator Privileges from an Admin or Owner



<iq from='darkcave@macbeth.shakespeare.lit'

    id='modtest'

    to='crone1@shakespeare.lit/desktop'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='secondwitch' role='participant'/>

  </query>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



9.8 Modifying the Moderator List



An admin may want to modify the moderator list. To do so, the admin first requests the moderator list by querying the room for all users with a role of 'moderator'.



Example 126. Admin Requests Moderator List



<iq from='crone1@shakespeare.lit/desktop'

    id='mod3'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item role='moderator'/>

  </query>

</iq>

    



The service MUST then return the moderator list to the admin; each item MUST include the 'jid', 'nick', and 'role' attributes and SHOULD include the 'affiliation' attribute:



Example 127. Service Sends Moderator List to Admin



<iq from='darkcave@macbeth.shakespeare.lit'

    id='mod3'

    to='crone1@shakespeare.lit/desktop'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='member'

          jid='hag66@shakespeare.lit/pda'

          nick='thirdwitch'

          role='moderator'/>

  </query>

</iq>

    



The admin MAY then modify the moderator list. In order to do so, the admin MUST send the changed items (i.e., only the "delta") back to the service; each item MUST include the 'jid' attribute and 'role' attribute (normally set to a value of "member" or "participant") but SHOULD NOT include the 'nick' attribute and MUST NOT include the 'affiliation' attribute (which is used to manage affiliations such as admin rather than the moderator role):



Example 128. Admin Sends Modified Moderator List to Service



<iq from='crone1@shakespeare.lit/desktop'

    id='mod4'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item jid='hag66@shakespeare.lit/pda'

          role='participant'/>

    <item jid='hecate@shakespeare.lit/broom'

          role='moderator'/>

  </query>

</iq>

    



The service MUST modify the moderator list and then inform the admin of success:



Example 129. Service Informs Admin of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='mod4'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence for any affected individuals to all occupants, indicating the change in moderator privileges by sending the appropriate extended presence stanzas as described in the foregoing use cases.



As noted, moderator privileges cannot be revoked from a room owner or room admin. If a room admin attempts to revoke moderator privileges from such a user by modifying the moderator list, the service MUST deny the request and return a <not-allowed/> error to the sender:



Example 130. Service Returns Error on Attempt to Revoke Moderator Privileges from an Admin or Owner



<iq from='darkcave@macbeth.shakespeare.lit'

    id='modtest'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item jid='hecate@shakespeare.lit/broom'

          nick='Hecate'

          role='participant'/>

  </query>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



9.9 Approving Registration Requests



If a service does not automatically accept requests to register with a room, it MAY provide a way for room admins to approve or deny registration requests over Jabber (alternatively, it could provide a web interface or some other admin tool). The simplest way to do so is for the service to send a <message/> stanza to the room admin(s) when the registration request is received, where the <message/> stanza contains a Data Form asking for approval or denial of the request. The following Data Form is RECOMMENDED but implementations MAY use a different form entirely, or supplement the following form with additional fields.



Example 131. Registration Request Approval Form



<message from='darkcave@macbeth.shakespeare.lit'

         id='approve'

         to='crone1@shakespeare.lit/pda'>

  <x xmlns='jabber:x:data' type='form'>

    <title>Registration request</title>

    <instructions>

      To approve this registration request, select the

      &quot;Allow this person to register with the room?&quot;

      checkbox and click OK. To skip this request, click the 

      cancel button.

    </instructions>

    <field var='FORM_TYPE' type='hidden'>

        <value>http://jabber.org/protocol/muc#register</value>

    </field>

    <field var='muc#register_first'

           type='text-single'

           label='First Name'>

      <value>Brunhilde</value>

    </field>

    <field var='muc#register_last'

           type="text-single"

           label="Last Name">

      <value>Entwhistle-Throckmorton</value>

    </field>

    <field var='muc#register_roomnick'

           type="text-single"

           label="Desired Nickname">

      <value>thirdwitch</value>

    </field>

    <field var='muc#register_url'

           type="text-single"

           label="User URL">

      <value>http://witchesonline/~hag66/</value>

    </field>

    <field var='muc#register_email'

           type="text-single"

           label="Email Address">

      <value>hag66@witchesonline</value>

    </field>

    <field var='muc#register_faqentry'

           type="text-single"

           label="FAQ Entry">

      <value>Just another witch.</value>

    </field>

    <field var='muc#register_allow'

           type='boolean'

           label='Allow this person to register with the room?'>

      <value>0</value>

    </field>

  </x>

</message>

    



If the admin approves the registration request, the service shall register the user with the room.



More advanced registration approval mechanisms (e.g., retrieving a list of registration requests using Ad-Hoc Commands [18] as is done in Publish-Subscribe [19]) are out of scope for this document.

10. Owner Use Cases



Every room MUST have at least one owner, and that owner (or a successor) is a long-lived attribute of the room for as long as the room exists (e.g., the owner does not lose ownership on exiting a persistent room). This document assumes that the (initial) room owner is the individual who creates the room and that only a room owner has the right to change defining room configuration settings such as the room type. Ideally, room owners will be able to specify not only the room types (password-protected, members-only, etc.) but also certain attributes of the room as listed in the Requirements section of this document. In addition, it would be good if an owner were able to specify the JIDs of other owners, but that shall be determined by the implementation.



In order to provide the necessary flexibility for a wide range of configuration options, Data Forms (XEP-0004) shall be used for room configuration, triggered by use of the 'http://jabber.org/protocol/muc' namespace. That is, if an entity does not include the MUC namespace in its room join/create request, then the service shall create the room and not wait for configuration via Data Forms before creating the room (this ensures backwards-compatibility with the old "groupchat 1.0" protocol); however, if the room join/create request includes the MUC extension, then the service shall require configuration via Data Forms before creating and unlocking the room.



Note: The configuration options shown below address all of the features and room types listed in the requirements section of this document; however, the exact configuration options and form layout shall be determined by the implementation or specific deployment. Also, these are examples only and are not intended to define the only allowed or required configuration options for rooms. A given implementation or deployment MAY choose to provide additional configuration options (profanity filters, setting the default language for a room, message logging, etc.), which is why the use of the 'jabber:x:data' protocol is valuable here.

10.1 Creating a Room

10.1.1 General Considerations



The privilege to create rooms MAY be restricted to certain users or MAY be reserved to an administrator of the service. If access is restricted and a user attempts to create a room, the service MUST return a <not-allowed/> error:



Example 132. Service Informs User of Inability to Create a Room



<presence

    from='darkcave@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <error code='405' type='cancel'>

    <not-allowed xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</presence>

      



If access is not restricted, the service MUST allow the user to create a room as described below.



From the perspective of room creation, there are in essence two kinds of rooms:



    *



      "Instant rooms" -- these are available for immediate access and are automatically created based on some default configuration.

    *



      "Reserved rooms" -- these are manually configured by the room creator before anyone is allowed to enter.



The workflow for creating and configuring such rooms is as follows:



   1.



      The user MUST send presence to <room@service/nick> and signal his or her support for the Multi-User Chat protocol by including extended presence information in an empty <x/> child element qualified by the 'http://jabber.org/protocol/muc' namespace (note the lack of an '#owner' or '#user' fragment).

   2.



      If this user is allowed to create a room and the room does not yet exist, the service MUST create the room according to some default configuration, assign the requesting user as the initial room owner, and add the owner to the room but not allow anyone else to enter the room (effectively "locking" the room). The initial presence stanza received by the owner from the room MUST include extended presence information indicating the user's status as an owner and acknowledging that the room has been created (via status code 201) and is awaiting configuration.

   3.



      If the initial room owner would like to create and configure a reserved room, the room owner MUST then request a configuration form by sending an IQ stanza of type "get" to the room containing an empty <query/> element qualified by the 'http://jabber.org/protocol/muc#owner' namespace, then complete Steps 4 and 5. If the room owner would prefer to create an instant room, the room owner MUST send a query element qualified by the 'http://jabber.org/protocol/muc#owner' namespace and containing an empty <x/> element of type "submit" qualified by the 'jabber:x:data' namespace, then skip to Step 6.

   4.



      If the room owner requested a configuration form, the service MUST send an IQ to the room owner containing a configuration form qualified by the 'jabber:x:data' namespace. If there are no configuration options available, the room MUST return an empty query element to the room owner.

   5.



      The initial room owner SHOULD provide a starting configuration for the room (or accept the default configuration) by sending an IQ of type "set" containing the completed configuration form. Alternatively, the room owner MAY cancel the configuration process. (An implementation MAY set a timeout for initial configuration, such that if the room owner does not configure the room within the timeout period, the room owner is assumed to have accepted the default configuration or to have cancelled the configuration process.)

   6.



      Once the service receives the completed configuration form from the initial room owner (or receives a request for an instant room), the service MUST "unlock" the room (i.e., allow other users to enter the room) and send an IQ of type "result" to the room owner. If the service receives a cancellation, it MUST destroy the room.



The protocol for this workflow is shown in the examples below.



First, the Jabber user MUST send presence to the room, including an empty <x/> element qualified by the 'http://jabber.org/protocol/muc' namespace (this is the same stanza sent when seeking to enter a room).



Example 133. Jabber User Creates a Room and Signals Support for Multi-User Chat



<presence

    from='crone1@shakespeare.lit/desktop'

    to='darkcave@macbeth.shakespeare.lit/firstwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>

      



If the room does not yet exist, the service SHOULD create the room (subject to local policies regarding room creation), assign the bare JID of the requesting user as the owner, add the owner to the room, and acknowledge successful creation of the room by sending a presence stanza of the following form:



Example 134. Service Acknowledges Room Creation



<presence

    from='darkcave@macbeth.shakespeare.lit/firstwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='owner'

          role='moderator'/>

    <status code='201'/>

  </x>

</presence>

      



After receiving notification that the room has been created, the room owner needs to decide whether to accept the default room configuration (i.e., create an "instant room") or configure the room to have something other than the default room configuration (i.e., create a "reserved room"). The protocol flows for completing those two use cases are shown in the following sections.



Note: If the presence stanza sent to a nonexistent room does not include an <x/> element qualified by the 'http://jabber.org/protocol/muc' namespace as shown above, the service SHOULD create a default room without delay (i.e., it MUST assume that the client supports "groupchat 1.0" rather than Multi-User Chat and therefore it MUST NOT lock the room while waiting for the room creator to either accept an instant room or configure a reserved room).

10.1.2 Creating an Instant Room



If the initial room owner wants to accept the default room configuration (i.e., create an "instant room"), the room owner MUST decline an initial configuration form by sending an IQ set to the <room@service> itself containing a <query/> element qualified by the 'http://jabber.org/protocol/muc#owner' namespace, where the only child of the <query/> is an empty <x/> element that is qualified by the 'jabber:x:data' namespace and that possesses a 'type' attribute whose value is "submit":



Example 135. Owner Requests Instant Room



<iq from='crone1@shakespeare.lit/desktop'

    id='create1'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <x xmlns='jabber:x:data' type='submit'/>

  </query>

</iq>

      



The service MUST then unlock the room and allow other entities to join it.

10.1.3 Creating a Reserved Room



If the initial room owner wants to create and configure a reserved room, the room owner MUST request an initial configuration form by sending an IQ get to the <room@service> itself containing an empty <query/> element qualified by the 'http://jabber.org/protocol/muc#owner' namespace:



Example 136. Owner Requests Configuration Form



<iq from='crone1@shakespeare.lit/desktop'

    id='create1'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#owner'/>

</iq>

      



If the room does not already exist, the service MUST return an initial room configuration form to the user. (Note: The following example shows a representative sample of configuration options. A full list of x:data fields registered for use in room creation and configuration is maintained by the XMPP Registrar; see the XMPP Registrar Considerations section of this document.)



Example 137. Service Sends Configuration Form



<iq from='darkcave@macbeth.shakespeare.lit'

    id='create1'

    to='crone1@shakespeare.lit/desktop'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <x xmlns='jabber:x:data' type='form'>

      <title>Configuration for "darkcave" Room</title>

      <instructions>

          Your room darkcave@macbeth has been created!

          The default configuration is as follows:

            - No logging

            - No moderation

            - Up to 20 occupants

            - No password required

            - No invitation required

            - Room is not persistent

            - Only admins may change the subject

            - Presence broadcasted for all users

          To accept the default configuration, click OK. To

          select a different configuration, please complete

          this form.

      </instructions>

      <field

          type='hidden'

          var='FORM_TYPE'>

        <value>http://jabber.org/protocol/muc#roomconfig</value>

      </field>

      <field

          label='Natural-Language Room Name'

          type='text-single'

          var='muc#roomconfig_roomname'/>

      <field

          label='Short Description of Room'

          type='text-single'

          var='muc#roomconfig_roomdesc'/>

      <field

          label='Natural Language for Room Discussions'

          type='text-single'

          var='muc#roomconfig_lang'/>

      <field

          label='Enable Public Logging?'

          type='boolean'

          var='muc#roomconfig_enablelogging'>

        <value>0</value>

      </field>

      <field

          label='Allow Occupants to Change Subject?'

          type='boolean'

          var='muc#roomconfig_changesubject'>

        <value>0</value>

      </field>

      <field

          label='Allow Occupants to Invite Others?'

          type='boolean'

          var='muc#roomconfig_allowinvites'>

        <value>0</value>

      </field>

      <field

          label='Maximum Number of Occupants'

          type='list-single'

          var='muc#roomconfig_maxusers'>

        <value>20</value>

        <option label='10'><value>10</value></option>

        <option label='20'><value>20</value></option>

        <option label='30'><value>30</value></option>

        <option label='50'><value>50</value></option>

        <option label='100'><value>100</value></option>

        <option label='None'><value>none</value></option>

      </field>

      <field

          label='Roles for which Presence is Broadcast'

          type='list-multi'

          var='muc#roomconfig_presencebroadcast'>

        <value>moderator</value>

        <value>participant</value>

        <value>visitor</value>

        <option label='Moderator'><value>moderator</value></option>

        <option label='Participant'><value>participant</value></option>

        <option label='Visitor'><value>visitor</value></option>

      </field>

      <field

          label='Make Room Publicly Searchable?'

          type='boolean'

          var='muc#roomconfig_publicroom'>

        <value>1</value>

      </field>

      <field

          label='Make Room Persistent?'

          type='boolean'

          var='muc#roomconfig_persistentroom'>

        <value>0</value>

      </field>

      <field

          label='Make Room Moderated?'

          type='boolean'

          var='muc#roomconfig_moderatedroom'>

        <value>0</value>

      </field>

      <field

          label='Make Room Members-Only?'

          type='boolean'

          var='muc#roomconfig_membersonly'>

        <value>0</value>

      </field>

      <field

          label='Password Required to Enter?'

          type='boolean'

          var='muc#roomconfig_passwordprotectedroom'>

        <value>0</value>

      </field>

      <field type='fixed'>

        <value>

          If a password is required to enter this room,

          you must specify the password below.

        </value>

      </field>

      <field

          label='Password'

          type='text-private'

          var='muc#roomconfig_roomsecret'/>

      <field

          label='Who May Discover Real JIDs?'

          type='list-single'

          var='muc#roomconfig_whois'>

        <option label='Moderators Only'>

          <value>moderators</value>

        </option>

        <option label='Anyone'>

          <value>anyone</value>

        </option>

      </field>

      <field type='fixed'>

        <value>

          You may specify additional people who have

          administrative privileges in the room. Please

          provide one Jabber ID per line.

        </value>

      </field>

      <field

          label='Room Admins'

          type='jid-multi'

          var='muc#roomconfig_roomadmins'/>

      <field type='fixed'>

        <value>

          You may specify additional owners for this

          room. Please provide one Jabber ID per line.

        </value>

      </field>

      <field

          label='Room Owners'

          type='jid-multi'

          var='muc#roomconfig_roomowners'/>

    </x>

  </query>

</iq>

      



Note: The _whois configuration option specifies whether the room is non-anonymous (a value of "anyone"), semi-anonymous (a value of "moderators"), or fully anonmyous (a value of "none", not shown here).



If there are no configuration options available, the service MUST return an empty query element to the room owner:



Example 138. Service Informs Owner that No Configuration is Possible



<iq from='darkcave@macbeth.shakespeare.lit'

    id='create1'

    to='crone1@shakespeare.lit/desktop'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#owner'/>

</iq>

      



The room owner SHOULD then fill out the form and submit it to the service.



Example 139. Owner Submits Configuration Form



<iq from='crone1@shakespeare.lit/desktop'

    id='create2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <x xmlns='jabber:x:data' type='submit'>

      <field var='FORM_TYPE'>

        <value>http://jabber.org/protocol/muc#roomconfig</value>

      </field>

      <field var='muc#roomconfig_roomname'>

        <value>A Dark Cave</value>

      </field>

      <field var='muc#roomconfig_roomdesc'>

        <value>The place for all good witches!</value>

      </field>

      <field var='muc#roomconfig_enablelogging'>

        <value>0</value>

      </field>

      <field var='muc#roomconfig_changesubject'>

        <value>1</value>

      </field>

      <field var='muc#roomconfig_allowinvites'>

        <value>0</value>

      </field>

      <field var='muc#roomconfig_maxusers'>

        <value>10</value>

      </field>

      <field var='muc#roomconfig_publicroom'>

        <value>0</value>

      </field>

      <field var='muc#roomconfig_persistentroom'>

        <value>0</value>

      </field>

      <field var='muc#roomconfig_moderatedroom'>

        <value>0</value>

      </field>

      <field var='muc#roomconfig_membersonly'>

        <value>0</value>

      </field>

      <field var='muc#roomconfig_passwordprotectedroom'>

        <value>1</value>

      </field>

      <field var='muc#roomconfig_roomsecret'>

        <value>cauldronburn</value>

      </field>

      <field var='muc#roomconfig_whois'>

        <value>moderators</value>

      </field>

      <field var='muc#roomconfig_roomadmins'>

        <value>wiccarocks@shakespeare.lit</value>

        <value>hecate@shakespeare.lit</value>

      </field>

    </x>

  </query>

</iq>

      



If room creation is successful, the service MUST inform the new room owner of success:



Example 140. Service Informs New Room Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='create2'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

      



If the room creation fails because the specified room configuration options violate one or more service policies (e.g., because the password for a password-protected room is blank), the service MUST return a <not-acceptable/> error.



Example 141. Service Informs Owner that Requested Configuration Options Are Unacceptable



<iq from='darkcave@macbeth.shakespeare.lit'

    id='create2'

    to='crone1@shakespeare.lit/desktop'

    type='error'>

  <error type='modify'>

    <not-acceptable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

      



Alternatively, the room owner MAY cancel the configuration process:



Example 142. Owner Cancels Initial Configuration



<iq from='crone1@shakespeare.lit/desktop'

    id='create2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <x xmlns='jabber:x:data' type='cancel'/>

  </query>

</iq>

      



If the room owner cancels the initial configuration, the service SHOULD destroy the room, making sure to send unavailable presence to the room owner (see the "Destroying a Room" use case for protocol details).



If the room owner becomes unavailable for any reason before submitting the form (e.g., a lost connection), the service will receive a presence stanza of type "unavailable" from the owner to the owner's <room@service/nick> or to <room@service> (or both). The service MUST then destroy the room, sending a presence stanza of type "unavailable" from the room to the owner including a <destroy/> element and reason (if provided) as defined in the Destroying a Room section of this document.

10.1.4 Requesting a Unique Room Name



In some situations (e.g., when Converting a One-to-One Chat Into a Conference), the room creator may want to request a unique room name before attempting to create the room (e.g., to avoid the possibility of a room conflict). In order to facilitate this, a service MAY support the feature described in this section. (If a service does support this feature, it MUST return a feature of "http://jabber.org/protocol/muc#unique" in its response to service discovery information requests.)



The room creator requests a unique room name by sending an IQ-get to the service itself, containing an empty <unique/> element qualified by the 'http://jabber.org/protocol/muc#unique' namespace:



Example 143. Entity Requests Unique Room Name



<iq from='crone1@shakespeare.lit/desktop'

    id='unique1'

    to='macbeth.shakespeare.lit'

    type='get'>

  <unique xmlns='http://jabber.org/protocol/muc#unique'/>

</iq>

      



If the service supports this feature, it SHOULD return a unique room name as the XML character data of the <unique/> element:



Example 144. Service Returns Unique Room Name



<iq from='macbeth.shakespeare.lit'

    id='unique1'

    to='crone1@shakespeare.lit/desktop'

    type='result'>

  <unique xmlns='http://jabber.org/protocol/muc#unique'>

    6d9423a55f499b29ad20bf7b2bdea4f4b885ead1

  </unique>

</iq>

      



The service MAY refuse to return a unique room name to entities that are not entitled to create rooms, entities that have sent an excessive number of requests for unique room names, etc.



The service MAY use any algorithm that ensures the creation of a room name that will be permanently unique in the context of the service (e.g., a SHA-1 hash of the requesting JID, datetime, and random salt).



The room creator would then use the XML character data of the <unique/> element as the node identifier portion of the room JID it requests:



Example 145. Owner Creates Room With Unique Name



<presence 

    from='crone1@shakespeare.lit/desktop'

    to='6d9423a55f499b29ad20bf7b2bdea4f4b885ead1@macbeth.shakespeare.lit/firstwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>

      



10.2 Subsequent Room Configuration



At any time after specifying the initial configuration of the room, a room owner may want to change the configuration. In order to initiate this process, a room owner MUST request a new configuration form from the room by sending an IQ to <room@service> containing an empty <query/> element qualified by the 'http://jabber.org/protocol/muc#owner' namespace.



Example 146. Owner Requests Configuration Form



<iq from='crone1@shakespeare.lit/desktop'

    id='config1'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#owner'/>

</iq>

    



If the <user@host> of the 'from' address does not match the bare JID of a room owner, the service MUST return a <forbidden/> error to the sender:



Example 147. Service Denies Configuration Access to Non-Owner



<iq from='darkcave@macbeth.shakespeare.lit'

    id='configures'

    to='wiccarocks@shakespeare.lit/laptop'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#owner'/>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



Otherwise, the service MUST send a configuration form to the room owner with the current options set as defaults:



Example 148. Service Sends Configuration Form to Owner



<iq from='darkcave@macbeth.shakespeare.lit'

    id='config1'

    to='crone1@shakespeare.lit/desktop'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <x xmlns='jabber:x:data' type='form'>

      <title>Configuration for "darkcave" Room</title>

      <instructions>

        Complete this form to make changes to

        the configuration of your room.

      </instructions>

      <field

          type='hidden'

          var='FORM_TYPE'>

        <value>http://jabber.org/protocol/muc#roomconfig</value>

      </field>

      <field

          label='Natural-Language Room Name'

          type='text-single'

          var='muc#roomconfig_roomname'>

        <value>A Dark Cave</value>

      </field>

      <field

          label='Short Description of Room'

          type='text-single'

          var='muc#roomconfig_roomdesc'>

        <value>The place for all good witches!</value>

      </field>

      <field

          label='Enable Public Logging?'

          type='boolean'

          var='muc#roomconfig_enablelogging'>

        <value>0</value>

      </field>

      <field

          label='Allow Occupants to Change Subject?'

          type='boolean'

          var='muc#roomconfig_changesubject'>

        <value>0</value>

      </field>

      <field

          label='Allow Occupants to Invite Others?'

          type='boolean'

          var='muc#roomconfig_allowinvites'>

        <value>0</value>

      </field>

      <field

          label='Maximum Number of Occupants'

          type='list-single'

          var='muc#roomconfig_maxusers'>

        <value>10</value>

        <option label='10'><value>10</value></option>

        <option label='20'><value>20</value></option>

        <option label='30'><value>30</value></option>

        <option label='50'><value>50</value></option>

        <option label='100'><value>100</value></option>

        <option label='None'><value>none</value></option>

      </field>

      <field

          label='Roles for which Presence is Broadcast'

          type='list-multi'

          var='muc#roomconfig_presencebroadcast'>

        <value>moderator</value>

        <value>participant</value>

        <value>visitor</value>

        <option label='Moderator'><value>moderator</value></option>

        <option label='Participant'><value>participant</value></option>

        <option label='Visitor'><value>visitor</value></option>

      </field>

      <field

          label='Make Room Publicly Searchable?'

          type='boolean'

          var='muc#roomconfig_publicroom'>

        <value>0</value>

      </field>

      <field

          label='Make Room Persistent?'

          type='boolean'

          var='muc#roomconfig_persistentroom'>

        <value>0</value>

      </field>

      <field

          label='Make Room Moderated?'

          type='boolean'

          var='muc#roomconfig_moderatedroom'>

        <value>0</value>

      </field>

      <field

          label='Make Room Members Only?'

          type='boolean'

          var='muc#roomconfig_membersonly'>

        <value>0</value>

      </field>

      <field

          label='Password Required for Entry?'

          type='boolean'

          var='muc#roomconfig_passwordprotectedroom'>

        <value>1</value>

      </field>

      <field type='fixed'>

        <value>

          If a password is required to enter this room,

          you must specify the password below.

        </value>

      </field>

      <field

          label='Password'

          type='text-private'

          var='muc#roomconfig_roomsecret'>

        <value>cauldronburn</value>

      </field>

      <field

          label='Who May Discover Real JIDs?'

          type='list-single'

          var='muc#roomconfig_whois'>

        <value>moderators</value>

        <option label='Moderators Only'>

          <value>moderators</value>

        </option>

        <option label='Anyone'>

          <value>anyone</value>

        </option>

      </field>

      <field type='fixed'>

        <value>

          You may specify additional people who have

          administrative privileges in the room. Please

          provide one Jabber ID per line.

        </value>

      </field>

      <field

          label='Room Admins'

          type='jid-multi'

          var='muc#roomconfig_roomadmins'>

        <value>wiccarocks@shakespeare.lit</value>

        <value>hecate@shakespeare.lit</value>

      </field>

      <field type='fixed'>

        <value>

          You may specify additional owners for this

          room. Please provide one Jabber ID per line.

        </value>

      </field>

      <field

          label='Room Owners'

          type='jid-multi'

          var='muc#roomconfig_roomowners'/>

    </x>

  </query>

</iq>

    



If there are no configuration options available, the service MUST return an empty query element to the room owner as shown in the previous use case.



The room owner SHOULD then submit the form with updated configuration information.



Alternatively, the room owner MAY cancel the configuration process:



Example 149. Owner Cancels Subsequent Configuration



<iq from='crone1@shakespeare.lit/desktop'

    id='config2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <x xmlns='jabber:x:data' type='cancel'/>

  </query>

</iq>

    



If the room owner cancels the subsequent configuration, the service MUST leave the configuration of the room as it was before the room owner initiated the subsequent configuration process.



If as a result of a change in the room configuration a room admin loses administrative privileges while the admin is in the room, the room MUST send updated presence for that individual to all occupants, denoting the change in status by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "member" and the 'role' attribute set to a value of "participant" or "visitor" as appropriate for the affiliation level and the room type:



Example 150. Service Notes Loss of Admin Affiliation



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='participant'/>

  </x>

</presence>

.

.

.

    



If as a result of a change in the room configuration a user gains administrative privileges while the user is in the room, the room MUST send updated presence for that individual to all occupants, denoting the change in status by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "admin" and the 'role' attribute set to a value of "admin":



Example 151. Service Notes Gain of Admin Affiliation to All Users



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='admin'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



If as a result of a change in the room configuration a room owner loses owner privileges while that owner is in the room, the room MUST send updated presence for that individual to all occupants, denoting the change in status by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "admin" and the 'role' attribute set to an appropriate value given the affiliation and room type ("moderator" is recommended).



Example 152. Service Notes Loss of Owner Affiliation



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='admin'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



A service MUST NOT allow an owner to revoke his or her own ownership privileges if there are no other owners; if an owner attempts to do this, the service MUST return a <conflict/> error to the owner. However, a service SHOULD allow an owner to revoke his or her own ownership privileges if there are other owners.



If as a result of a change in the room configuration a user gains ownership privileges while the user is in the room, the room MUST send updated presence for that individual to all occupants, denoting the change in status by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "owner" and the 'role' attribute set to an appropriate value given the affiliation and room type ("moderator" is recommended).



Example 153. Service Notes Gain of Owner Affiliation to All Users



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='owner'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



If as a result of a change in the room configuration the room type is changed to members-only but there are non-members in the room, the service MUST remove any non-members from the room and include a status code of 322 in the presence unavailable stanzas sent to those users as well as any remaining occupants.

10.2.1 Notification of Configuration Changes



A room MUST send notification to all occupants when the room configuration changes in a way that has an impact on the privacy or security profile of the room. This notification shall consist of a <message/> stanza containing an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace, which shall contain only a <status/> element with an appropriate value for the 'code' attribute. Here is an example:



Example 154. Configuration Status Code



<message from='darkcave@macbeth.shakespeare.lit'

         to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <status code='170'/>

  </x>

</message>

      



The codes to be generated as a result of a privacy-related change in room configuration are as follows:



    * If room logging is now enabled, status code 170.

    * If room logging is now disabled, status code 171.

    * If the room is now non-anonymous, status code 172.

    * If the room is now semi-anonymous, status code 173.

    * If the room is now fully-anonymous, status code 174.



For any other configuration change, the room SHOULD send status code 104 so that interested occupants can retrieve the updated room configuration if desired.

10.3 Granting Ownership Privileges



If allowed by an implementation, an owner MAY grant ownership privileges to another user; this is done by changing the user's affiliation to "owner":



Example 155. Owner Grants Ownership Privileges



<iq from='crone1@shakespeare.lit/desktop'

    id='owner1'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='owner'

          jid='hecate@shakespeare.lit'/>

  </query>

</iq>

    



The service MUST add the user to the owner list and then inform the owner of success:



Example 156. Service Informs Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='owner1'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



If the user is in the room, the service MUST then send updated presence from this individual to all occupants, indicating the granting of ownership privileges by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "owner" and the 'role' attribute set to an appropriate value given the affiliation and room type ("moderator" is recommended).



Example 157. Service Sends Notice of Ownership Privileges to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/hecate'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='owner'

          jid='hecate@shakespeare.lit/broom'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



10.4 Revoking Ownership Privileges



An implementation MAY allow an owner to revoke another user's ownership privileges; this is done by changing the user's affiliation to something other than "owner":



Example 158. Owner Revokes Ownership Privileges



<iq from='crone1@shakespeare.lit/desktop'

    id='owner2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='admin'

          jid='hecate@shakespeare.lit'/>

  </query>

</iq>

    



A service MUST NOT allow an owner to revoke his or her own ownership privileges if there are no other owners; if an owner attempts to do this, the service MUST return a <conflict/> error to the owner. However, a service SHOULD allow an owner to revoke his or her own ownership privileges if there are other owners.



If an implementation does not allow one owner to revoke another user's ownership privileges, the implementation MUST return a <not-authorized/> error to the owner who made the request.



In all other cases, the service MUST remove the user from the owner list and then inform the owner of success:



Example 159. Service Informs Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='owner2'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



If the user is in the room, the service MUST then send updated presence from this individual to all occupants, indicating the loss of ownership privileges by sending a presence element that contains an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value other than "owner" and the 'role' attribute set to an appropriate value:



Example 160. Service Notes Loss of Owner Affiliation



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='admin'

          jid='hecate@shakespeare.lit/broom'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



Note: Allowing an owner to remove another user's ownership privileges can compromise the control model for room management; therefore this feature is OPTIONAL, and implementations are encouraged to support owner removal through an interface that is open only to individuals with service-wide administrative privileges.

10.5 Modifying the Owner List



If allowed by an implementation, a room owner may want to modify the owner list. To do so, the owner first requests the owner list by querying the room for all users with an affiliation of 'owner'.



Example 161. Owner Requests Owner List



<iq from='bard@shakespeare.lit/globe'

    id='owner3'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='owner'/>

  </query>

</iq>

    



If the <user@host> of the 'from' address does not match the bare JID of a room owner, the service MUST return a <forbidden/> error to the sender.



Otherwise, the service MUST then return the owner list to the owner; each item MUST include the 'affiliation' and 'jid' attributes and MAY include the 'nick' and 'role' attributes for any owner that is currently an occupant:



Example 162. Service Sends Owner List to Owner



<iq from='darkcave@macbeth.shakespeare.lit'

    id='owner3'

    to='bard@shakespeare.lit/globe'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='owner'

          jid='crone1@shakespeare.lit'/>

  </query>

</iq>

    



The owner MAY then modify the owner list. In order to do so, the owner MUST send the changed items (i.e., only the "delta") back to the service; [20] each item MUST include the 'affiliation' and 'jid' attributes but SHOULD NOT include the 'nick' attribute and MUST NOT include the 'role' attribute (which is used to manage roles such as participant rather than the owner affiliation):



Example 163. Owner Sends Modified Owner List to Service



<iq from='bard@shakespeare.lit/globe'

    id='owner4'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='owner'

          jid='hecate@shakespeare.lit'/>

  </query>

</iq>

    



Only owners shall be allowed to modify the owner list. If a non-owner attempts to view or modify the owner list, the service MUST deny the request and return a <forbidden/> error to the sender:



Example 164. Service Returns Error on Attempt by Non-Owner to Modify Owner List



<iq from='darkcave@macbeth.shakespeare.lit'

    id='ownertest'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='owner' 

          jid='hecate@shakespeare.lit'/>

  </query>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



A service MUST NOT allow an owner to revoke his or her own ownership privileges if there are no other owners; if an owner attempts to do this, the service MUST return a <conflict/> error to the owner. However, a service SHOULD allow an owner to revoke his or her own ownership privileges if there are other owners.



In all other cases, the service MUST modify owner list and then inform the owner of success:



Example 165. Service Informs Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='owner4'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST also send presence notifications related to any affiliation changes that result from modifying the owner list as previously described.

10.6 Granting Administrative Privileges



An owner can grant administrative privileges to a member or unaffiliated user; this is done by changing the user's affiliation to "admin":



Example 166. Owner Grants Admin Privileges



<iq from='crone1@shakespeare.lit/desktop'

    id='admin1'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='admin'

          jid='wiccarocks@shakespeare.lit'/>

  </query>

</iq>

    



The service MUST add the user to the admin list and then inform the owner of success:



Example 167. Service Informs Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='admin1'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



If the user is in the room, the service MUST then send updated presence from this individual to all occupants, indicating the granting of administrative privileges by including an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value of "admin" and the 'role' attribute set to an appropriate value given the affiliation and room type.



Example 168. Service Sends Notice of Administrative Privileges to All Occupants



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='admin'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='moderator'/>

  </x>

</presence>

.

.

.

    



10.7 Revoking Administrative Privileges



An owner may want to revoke a user's administrative privileges; this is done by changing the user's affiliation to something other than "admin" or "owner":



Example 169. Owner Revokes Administrative Privileges



<iq from='crone1@shakespeare.lit/desktop'

    id='admin2'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='member'

          jid='wiccarocks@shakespeare.lit'/>

  </query>

</iq>

    



The service MUST remove the user from the admin list and then inform the owner of success:



Example 170. Service Informs Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='admin2'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST then send updated presence from this individual to all occupants, indicating the loss of administrative privileges by sending a presence element that contains an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child with the 'affiliation' attribute set to a value other than "admin" or "owner" and the 'role' attribute set to an appropriate value given the affiliation level and the room type:



Example 171. Service Notes Loss of Admin Affiliation



<presence

    from='darkcave@macbeth.shakespeare.lit/secondwitch'

    to='crone1@shakespeare.lit/desktop'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='member'

          jid='wiccarocks@shakespeare.lit/laptop'

          role='participant'/>

  </x>

</presence>

.

.

.

    



10.8 Modifying the Admin List



A room owner may want to modify the admin list. To do so, the owner first requests the admin list by querying the room for all users with an affiliation of 'admin'.



Example 172. Owner Requests Admin List



<iq from='bard@shakespeare.lit/desktopaffiliation

    id='admin3'

    to='darkcave@macbeth.shakespeare.lit'

    type='get'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='admin'/>

  </query>

</iq>

    



If the <user@host> of the 'from' address does not match the bare JID of a room owner, the service MUST return a <forbidden/> error to the sender.



Otherwise, the service MUST then return the admin list to the owner; each item MUST include the 'affiliation' and 'jid' attributes and MAY include the 'nick' and 'role' attributes for any admin that is currently an occupant:



Example 173. Service Sends Admin List to Owner



<iq from='darkcave@macbeth.shakespeare.lit'

    id='admin3'

    to='bard@shakespeare.lit/globe'

    type='result'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='admin'

          jid='wiccarocks@shakespeare.lit'

          nick='secondwitch'/>

    <item affiliation='admin'

          jid='hag66@shakespeare.lit'/>

  </query>

</iq>

    



The owner MAY then modify the admin list. In order to do so, the owner MUST send the changed items (i.e., only the "delta") back to the service; [21] each item MUST include the 'affiliation' attribute (normally set to a value of "admin" or "none") and 'jid' attribute but SHOULD NOT include the 'nick' attribute and MUST NOT include the 'role' attribute (which is used to manage roles such as participant rather than the admin affiliation):



Example 174. Owner Sends Modified Admin List to Service



<iq from='bard@shakespeare.lit/globe'

    id='admin4'

    to='darkcave@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='none'

          jid='hag66@shakespeare.lit'>

    </item>

    <item affiliation='admin'

          jid='hecate@shakespeare.lit'>

    </item>

  </query>

</iq>

    



Only owners shall be allowed to modify the admin list. If a non-owner attempts to view or modify the admin list, the service MUST deny the request and return a <forbidden/> error to the sender:



Example 175. Service Returns Error on Attempt by Non-Owner to Modify Admin List



<iq from='darkcave@macbeth.shakespeare.lit'

    id='admintest'

    to='hag66@shakespeare.lit/pda'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='admin' 

          jid='hecate@shakespeare.lit'/>

  </query>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



Otherwise, the service MUST modify the admin list and then inform the owner of success:



Example 176. Service Informs Owner of Success



<iq from='darkcave@macbeth.shakespeare.lit'

    id='admin4'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



The service MUST also send presence notifications related to any affiliation changes that result from modifying the admin list as previously described.

10.9 Destroying a Room



A room owner MUST be able to destroy a room, especially if the room is persistent. The workflow is as follows:



   1.



      The room owner requests that the room be destroyed, specifying a reason and an alternate venue if desired.

   2.



      The room removes all users from the room (including appropriate information about the alternate location and the reason for being removed) and destroys the room, even if it was defined as persistent.



Other than the foregoing, this document does not specify what (if anything) a MUC service implementation shall do as a result of a room destruction request. For example, if the room was defined as persistent, an implementation MAY choose to lock the room ID so that it cannot be re-used, redirect enter requests to the alternate venue, or invite the current participants to the new room; however, such behavior is OPTIONAL.



In order to destroy a room, the room owner MUST send an IQ set to the address of the room to be destroyed. The <iq/> stanza shall contain a <query/> element qualified by the 'http://jabber.org/protocol/muc#owner' namespace, which in turn shall contain a <destroy/> element. The address of the alternate venue MAY be provided as the value of the <destroy/> element's 'jid' attribute. A password for the alternate venue MAY be provided as the XML character data of a <password/> child element of the <destroy/> element. The reason for the room destruction MAY be provided as the XML character data of a <reason/> child element of the <destroy/> element.



The following examples illustrate the protocol elements to be sent and received:



Example 177. Owner Submits Room Destruction Request



<iq from='crone1@shakespeare.lit/desktop'

    id='begone'

    to='heath@macbeth.shakespeare.lit'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <destroy jid='darkcave@macbeth.shakespeare.lit'>

      <reason>Macbeth doth come.</reason>

    </destroy>

  </query>

</iq>

    



The service is responsible for removing all the occupants. It SHOULD NOT broadcast presence stanzas of type "unavailable" from all occupants, instead sending only one presence stanza of type "unavailable" to each occupant so that the user knows he or she has been removed from the room. If extended presence information specifying the JID of an alternate location and the reason for the room destruction was provided by the room owner, the presence stanza MUST include that information.



Example 178. Service Removes Each Occupant



<presence

    from='heath@macbeth.shakespeare.lit/firstwitch'

    to='crone1@shakespeare.lit/desktop'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'/>

    <destroy jid='darkcave@macbeth.shakespeare.lit'>

      <reason>Macbeth doth come.</reason>

    </destroy>

  </x>

</presence>



<presence

    from='heath@macbeth.shakespeare.lit/secondwitch'

    to='wiccarocks@shakespeare.lit/laptop'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'/>

    <destroy jid='darkcave@macbeth.shakespeare.lit'>

      <reason>Macbeth doth come.</reason>

    </destroy>

  </x>

</presence>



<presence

    from='heath@macbeth.shakespeare.lit/thirdwitch'

    to='hag66@shakespeare.lit/pda'

    type='unavailable'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <item affiliation='none' role='none'/>

    <destroy jid='darkcave@macbeth.shakespeare.lit'>

      <reason>Macbeth doth come.</reason>

    </destroy>

  </x>

</presence>

    



Example 179. Service Informs Owner of Successful Destruction



<iq from='heath@macbeth.shakespeare.lit'

    id='begone'

    to='crone1@shakespeare.lit/desktop'

    type='result'/>

    



If the <user@host> of the 'from' address received on a destroy request does not match the bare JID of a room owner, the service MUST return a <forbidden/> error to the sender:



Example 180. Service Denies Destroy Request Submitted by Non-Owner



<iq from='heath@macbeth.shakespeare.lit'

    id='destroytest'

    to='wiccarocks@shakespeare.lit/laptop'

    type='error'>

  <query xmlns='http://jabber.org/protocol/muc#owner'>

    <destroy jid='darkcave@macbeth.shakespeare.lit'>

      <reason>Macbeth doth come.</reason>

    </destroy>

  </query>

  <error code='403' type='auth'>

    <forbidden xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

    



11. Error and Status Codes

11.1 Error Codes



The error codes associated with the 'http://jabber.org/protocol/muc#user' namespace are fairly straightforward, as summarized in the following table. For detailed information about mapping legacy error codes to XMPP-style error types and conditions, refer to Error Condition Mappings [22]; implementations SHOULD support both legacy and XMPP error handling.



Table 8: Error Codes for http://jabber.org/protocol/muc#user Namespace

Code 	Type 	Element 	Context 	Purpose

401 	Error 	Presence 	Entering a room 	Inform user that a password is required

403 	Error 	Presence 	Entering a room 	Inform user that he or she is banned from the room

404 	Error 	Presence 	Entering a room 	Inform user that the room does not exist

405 	Error 	Presence 	Entering a room 	Inform user that room creation is restricted

406 	Error 	Presence 	Entering a room 	Inform user that the reserved roomnick must be used

407 	Error 	Presence 	Entering a room 	Inform user that he or she is not on the member list

409 	Error 	Presence 	Entering a room 	Inform user that his or her desired room nickname is in use or registered by another user

503 	Error 	Presence 	Entering a room 	Inform user that the maximum number of users has been reached



This document does not stipulate text strings (i.e., values of the XMPP <text/> element) associated with the foregoing error conditions.

11.2 Status Codes



Multi-User Chat uses a <status/> element (specifically, the 'code' attribute of the <status/> element) to communicate information about a user's status in a room. Over time, the number of status codes has grown quite large, and new status codes continue to be requested of the author. Therefore, these codes are now documented in a registry maintained by the XMPP Registrar. For details, refer to the Status Codes Registry section of this document.



Note: In general, MUC status codes tend to follow the "philosophy" of status codes that is implicit in RFC 2616 [23] and RFC 1893 [24] (1xx codes are informational, 2xx codes specify that it is fine to continue, 3xx codes specify redirects such as being kicked or banned, x3x codes refer to system status, x7x codes refer to security or policy matters, etc.).



Note: If the MUC protocol were being designed today, it would specify a more flexible, XML-friendly approach rather than hardcoded status numbers; however, at this point the pain of changing the status reporting system would be greater than the benefit of doing so, which is why the status code numbers remain in use. A future version of this document may define a more XMPP-like approach to status conditions, retaining the code numbers but supplementing them with more descriptive child elements as is done in RFC 3920.

12. Internationalization Considerations



As specified in RFC 3920, XMPP entities (including MUC rooms and MUC services) SHOULD respect the value of the 'xml:lang' attribute provided with any given stanza. However, simultaneous translation of groupchat messages is out of scope for this document.



The status and error codes defined herein enable a client implementation to present a localized interface; however, definition of the localized text strings for any given language community is out of scope for this document.



Although the labels for various data form fields are shown here in English, MUC clients SHOULD present localized text for these fields rather than the English text.

13. Security Considerations

13.1 User Authentication and Authorization



No room entrance authentication or authorization method more secure than cleartext passwords is defined or required by this document. However, the risks involved can mitigated by the use of channel encryption and strong authentication via TLS and SASL as described in RFC 3920.

13.2 End-to-End Encryption



No end-to-end message or session encryption method is specified herein. Users SHOULD NOT trust a service to keep secret any text sent through a room.

13.3 Privacy



Depending on room configuration, a room may publicly log all discussions held in the room. A service MUST warn the user that the room is publicly logged by returning a status code of "170" with the user's initial presence, and user's the client MUST so warn the user if the room discussion is logged (a user's client SHOULD also query the room for its configuration prior to allowing the user to enter in order to "pre-discover" whether the room is logged). A client MUST also warn the user if the room's configuration is subsequently modified to allow room logging (which the client will discover when the room sends status code 170). Note: In-room history is different from public room logging, and naturally a room cannot effectively prevent occupants from separately maintaining their own room logs, which may become public; users SHOULD exercise due caution and consider any room discussions to be effectively public.

13.4 Anonymity



Depending on room configuration, a room MAY expose each occupant's real JID to other occupants (if the room is non-anonymous) and will almost certainly expose each occupant's real JID to the room owners and administrators (if the room is not fully-anonymous). A service MUST warn the user that real JIDs are exposed in the room by returning a status code of "100" with the user's initial presence, and the user's client MUST so warn the user (a user's client SHOULD also query the room for its configuration prior to allowing the user to enter in order to "pre-discover" whether real JIDs are exposed in the room). A client MUST also warn the user if the room's configuration is subsequently modified from semi-anonymous or fully-anonymous to non-anonymous (which the client will discover when the room sends status code 172) and SHOULD warn the user if the room's configuration is subsequently modified from fully-anonymous to semi-anonymous (which the client will discover when the room sends status code 173).

14. IANA Considerations



This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [25].

15. XMPP Registrar Considerations



The XMPP Registrar [26] includes the following information in its registries.

15.1 Protocol Namespaces



The XMPP Registrar includes the following MUC-related namespaces in its registry of protocol namespaces:



    * http://jabber.org/protocol/muc

    * http://jabber.org/protocol/muc#admin

    * http://jabber.org/protocol/muc#owner

    * http://jabber.org/protocol/muc#unique

    * http://jabber.org/protocol/muc#user



15.2 Service Discovery Category/Type



A Multi-User Chat service or room is identified by the "conference" category and the "text" type within Service Discovery.

15.3 Service Discovery Features



There are many features related to a MUC service or room that can be discovered by means of Service Discovery. The most fundamental of these is the 'http://jabber.org/protocol/muc' namespace. In addition, a MUC room SHOULD provide information about the specific room features it implements, such as password protection and room moderation.



Registry Submission



<var>

  <name>http://jabber.org/protocol/muc#register</name>

  <desc>Support for the muc#register FORM_TYPE</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>http://jabber.org/protocol/muc#roomconfig</name>

  <desc>Support for the muc#roomconfig FORM_TYPE</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>http://jabber.org/protocol/muc#roominfo</name>

  <desc>Support for the muc#roominfo FORM_TYPE</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_hidden</name>

  <desc>Hidden room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_membersonly</name>

  <desc>Members-only room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_moderated</name>

  <desc>Moderated room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_nonanonymous</name>

  <desc>Non-anonymous room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_open</name>

  <desc>Open room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_passwordprotected</name>

  <desc>Password-protected room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_persistent</name>

  <desc>Persistent room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_public</name>

  <desc>Public room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_rooms</name>

  <desc>List of MUC rooms (each as a separate item)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_semianonymous</name>

  <desc>Semi-anonymous room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_temporary</name>

  <desc>Temporary room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_unmoderated</name>

  <desc>Unmoderated room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

<var>

  <name>muc_unsecured</name>

  <desc>Unsecured room in Multi-User Chat (MUC)</desc>

  <doc>XEP-0045</doc>

</var>

    



15.4 Well-Known Service Discovery Nodes



The well-known Service Discovery node 'http://jabber.org/protocol/muc#rooms' enables discovery of the rooms in which a user is an occupant.



The well-known Service Discovery node 'x-roomuser-item' enables a user to discover his or her registered roomnick from outside the room.



The well-known Service Discovery node 'http://jabber.org/protocol/muc#traffic' enables discovery of the namespaces that are allowed in traffic sent through a room (see the Allowable Traffic section of this document).

15.5 Field Standardization



Field Standardization for Data Forms [27] defines a process for standardizing the fields used within Data Forms qualified by a particular namespace. Within MUC, there are four uses of such forms: room registration (the "muc#register" FORM_TYPE), requesting voice and approving voice requests ("muc#request"), room configuration ("muc#roomconfig"), and service discovery extensions for room information ("muc#roominfo"). The reserved fields are defined below.

15.5.1 muc#register FORM_TYPE



Registry Submission



<form_type>

  <name>http://jabber.org/protocol/muc#register</name>

  <doc>XEP-0045</doc>

  <desc>

    Forms enabling user registration with a

    Multi-User Chat (MUC) room or admin approval

    of user registration requests.

  </desc>

  <field 

     var='muc#register_allow'

     type='boolean'

     label='Allow this person to register with the room?'/>

  <field

      var='muc#register_email'

      type='text-single'

      label='Email Address'/>

  <field

      var='muc#register_faqentry'

      type='text-multi'

      label='FAQ Entry'/>

  <field

      var='muc#register_first'

      type='text-single'

      label='First Name'/>

  <field

      var='muc#register_last'

      type='text-single'

      label='Last Name'/>

  <field

      var='muc#register_roomnick'

      type='text-single'

      label='Desired Nickname'/>

  <field

      var='muc#register_url'

      type='text-single'

      label='Your URL'/>

</form_type>

      



15.5.2 muc#request FORM_TYPE



Registry Submission



<form_type>

  <name>http://jabber.org/protocol/muc#request</name>

  <doc>XEP-0045</doc>

  <desc>

    Forms enabling voice requests in a 

    Multi-User Chat (MUC) room or admin

    approval of such requests.

  </desc>

  <field var='muc#role'

         type='text-single'

         label='Requested role'/>

  <field var='muc#jid'

         type='text-single'

         label='User ID'/>

  <field var='muc#roomnick'

         type='text-single'

         label='Room Nickname'/>

  <field var='muc#request_allow'

         type='boolean'

         label='Whether to grant voice'/>

</form_type>

      



15.5.3 muc#roomconfig FORM_TYPE



Registry Submission



<form_type>

  <name>http://jabber.org/protocol/muc#roomconfig</name>

  <doc>XEP-0045</doc>

  <desc>

    Forms enabling creation and configuration of

    a Multi-User Chat (MUC) room.

  </desc>

  <field

      var='muc#roomconfig_allowinvites'

      type='boolean'

      label='Whether to Allow Occupants to Invite Others'/>

  <field

      var='muc#roomconfig_changesubject'

      type='boolean'

      label='Whether to Allow Occupants to Change Subject'/>

  <field

      var='muc#roomconfig_enablelogging'

      type='boolean'

      label='Whether to Enable Public Logging of Room Conversations'/>

  <field

      var='muc#roomconfig_lang'

      type='text-single'

      label='Natural Language for Room Discussions'/>

  <field

      var='muc#roomconfig_pubsub'

      type='text-single'

      label='XMPP URI of Associated Publish-Subcribe Node'/>

  <field

      var='muc#roomconfig_maxusers'

      type='list-single'

      label='Maximum Number of Room Occupants'/>

  <field

      var='muc#roomconfig_membersonly'

      type='boolean'

      label='Whether an Make Room Members-Only'/>

  <field

      var='muc#roomconfig_moderatedroom'

      type='boolean'

      label='Whether to Make Room Moderated'/>

  <field

      var='muc#roomconfig_passwordprotectedroom'

      type='boolean'

      label='Whether a Password is Required to Enter'/>

  <field

      var='muc#roomconfig_persistentroom'

      type='boolean'

      label='Whether to Make Room Persistent'/>

  <field

      var='muc#roomconfig_presencebroadcast'

      type='list-multi'

      label='Roles for which Presence is Broadcast'/>

  <field

      var='muc#roomconfig_publicroom'

      type='boolean'

      label='Whether to Allow Public Searching for Room'/>

  <field

      var='muc#roomconfig_roomadmins'

      type='jid-multi'

      label='Full List of Room Admins'/>

  <field

      var='muc#roomconfig_roomdesc'

      type='text-single'

      label='Short Description of Room'/>

  <field

      var='muc#roomconfig_roomname'

      type='text-single'

      label='Natural-Language Room Name'/>

  <field

      var='muc#roomconfig_roomowners'

      type='jid-multi'

      label='Full List of Room Owners'/>

  <field

      var='muc#roomconfig_roomsecret'

      type='text-private'

      label='The Room Password'/>

  <field

      var='muc#roomconfig_whois'

      type='list-single'

      label='Affiliations that May Discover Real JIDs of Occupants'/>

</form_type>

      



15.5.4 muc#roominfo FORM_TYPE



Registry Submission



<form_type>

  <name>http://jabber.org/protocol/muc#roominfo</name>

  <doc>XEP-0045</doc>

  <desc>

    Forms enabling the communication of extended service discovery

    information about a Multi-User Chat (MUC) room.

  </desc>

  <field

      var='muc#roominfo_contactjid'

      type='jid-multi'

      label='Contact Addresses (normally, room owner or owners)'/>

  <field

      var='muc#roominfo_description'

      type='text-single'

      label='Short Description of Room'/>

  <field

      var='muc#roominfo_lang'

      type='text-single'

      label='Natural Language for Room Discussions'/>

  <field

      var='muc#roominfo_logs'

      type='text-single'

      label='URL for Archived Discussion Logs'/>

  <field

      var='muc#roominfo_occupants'

      type='text-single'

      label='Current Number of Occupants in Room'/>

  <field

      var='muc#roominfo_subject'

      type='text-single'

      label='Current Subject or Discussion Topic in Room'/>

</form_type>

      



15.6 Status Codes Registry

15.6.1 Process



The XMPP Registrar maintains a registry of values for the 'code' attribute of the <status/> element when qualified by the 'http://jabber.org/protocol/muc#user' namespace.



In order to submit new values to this registry, the registrant must define an XML fragment of the following form and either include it in the relevant XMPP Extension Protocol or send it to the email address <registrar@xmpp.org>:



<statuscode>

  <number>the three-digit code number</number>

  <stanza>the stanza type of which it is a child (message or presence)</desc>

  <context>the use case or situation in which the status is used</context>

  <purpose>a natural-language description of the meaning</purpose>

  <child>the descriptive child element (reserved for future use)</child>

</statuscode>

      



The registrant may register more than one status code at a time, each contained in a separate <statuscode/> element.

15.6.2 Initial Submission



As part of this document, the following status codes are registered:



<statuscode>

  <number>100</number>

  <stanza>message or presence</stanza>

  <context>Entering a room</context>

  <purpose>Inform user that any occupant is allowed to see the user's full JID</purpose>

</statuscode>

<statuscode>

  <number>101</number>

  <stanza>message (out of band)</stanza>

  <context>Affiliation change</context>

  <purpose>Inform user that his or her affiliation changed while not in the room</purpose>

</statuscode>

<statuscode>

  <number>102</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that room now shows unavailable members</purpose>

</statuscode>

<statuscode>

  <number>103</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that room now does not show unavailable members</purpose>

</statuscode>

<statuscode>

  <number>104</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>

    Inform occupants that a non-privacy-related room configuration change has occurred

  </purpose>

</statuscode>

<statuscode>

  <number>110</number>

  <stanza>presence</stanza>

  <context>Any room presence</context>

  <purpose>Inform user that presence refers to one of its own room occupants</purpose>

</statuscode>

<statuscode>

  <number>170</number>

  <stanza>message or initial presence</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that room logging is now enabled</purpose>

</statuscode>

<statuscode>

  <number>171</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that room logging is now disabled</purpose>

</statuscode>

<statuscode>

  <number>172</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that the room is now non-anonymous</purpose>

</statuscode>

<statuscode>

  <number>173</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that the room is now semi-anonymous</purpose>

</statuscode>

<statuscode>

  <number>174</number>

  <stanza>message</stanza>

  <context>Configuration change</context>

  <purpose>Inform occupants that the room is now fully-anonymous</purpose>

</statuscode>

<statuscode>

  <number>201</number>

  <stanza>presence</stanza>

  <context>Entering a room</context>

  <purpose>Inform user that a new room has been created</purpose>

</statuscode>

<statuscode>

  <number>210</number>

  <stanza>presence</stanza>

  <context>Entering a room</context>

  <purpose>Inform user that service has assigned or modified occupant's roomnick</purpose>

</statuscode>

<statuscode>

  <number>301</number>

  <stanza>presence</stanza>

  <context>Removal from room</context>

  <purpose>Inform user that he or she has been banned from the room</purpose>

</statuscode>

<statuscode>

  <number>303</number>

  <stanza>presence</stanza>

  <context>Exiting a room</context>

  <purpose>Inform all occupants of new room nickname</purpose>

</statuscode>

<statuscode>

  <number>307</number>

  <stanza>presence</stanza>

  <context>Removal from room</context>

  <purpose>Inform user that he or she has been kicked from the room</purpose>

</statuscode>

<statuscode>

  <number>321</number>

  <stanza>presence</stanza>

  <context>Removal from room</context>

  <purpose>Inform user that he or she is being removed from the room 

    because of an affiliation change</purpose>

</statuscode>

<statuscode>

  <number>322</number>

  <stanza>presence</stanza>

  <context>Removal from room</context>

  <purpose>Inform user that he or she is being removed from the room 

    because the room has been changed to members-only and the user 

    is not a member</purpose>

</statuscode>

<statuscode>

  <number>332</number>

  <stanza>presence</stanza>

  <context>Removal from room</context>

  <purpose>Inform user that he or she is being removed from the room 

    because of a system shutdown</purpose>

</statuscode>

      



15.7 URI Query Types



As authorized by XMPP URI Query Components [28], the XMPP Registrar maintains a registry of queries and key-value pairs for use in XMPP URIs (see <http://www.xmpp.org/registrar/querytypes.html>).

15.7.1 join



The "join" querytype is registered as a MUC-related action, with an optional key of "password".



Example 181. Join Action: IRI/URI



xmpp:darkcave@macbeth.shakespeare.lit?join

      



The application MUST either present an interface enabling the user to provide a room nickname or populate the room nickname based on configured preferences or nickname discovery.



Example 182. Join Action: Resulting Stanza



<presence to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>

      



The join action MAY include a password for the room. Naturally, access to a URI that includes a room password MUST be appropriately controlled.



Example 183. Join Action with Password: IRI/URI



xmpp:darkcave@macbeth.shakespeare.lit?join;password=cauldronburn

      



Example 184. Join Action with Password: Resulting Stanza



<presence to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'>

    <password>cauldronburn</password>

  </x>

</presence>

      



The following submission registers the "join" querytype.



<querytype>

  <name>join</name>

  <proto>http://jabber.org/protocol/muc</proto>

  <desc>enables joining a multi-user chat room</desc>

  <doc>XEP-0045</doc>

  <keys>

    <key>

      <name>password</name>

      <desc>the password required to enter a multi-user chat room</desc>

    </key>

  </keys>

</querytype>

      



15.7.2 invite



The "invite" querytype is registered as a MUC-related action, with an optional key of "jid".



Example 185. Invite Action: IRI/URI



xmpp:darkcave@macbeth.shakespeare.lit?invite;jid=hecate@shakespeare.lit

      



If the joining user is not yet in the room, the application MUST send two stanzas: the first to join the room and the second to invite the other individual. If the joining user is in the room already, the application shall send only the invitation stanza.



Example 186. Invite Action: Resulting Stanza(s)



<presence to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>



<message to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='hecate@shakespeare.lit'/>

  </x>

</message>

      



The URI may include multiple invitees:



Example 187. Invite Action With Multiple Invitees: IRI/URI



xmpp:darkcave@macbeth.shakespeare.lit?invite;jid=hecate@shakespeare.lit;jid=bard@shakespeare.lit

      



Example 188. Invite Action With Multiple Invitees: Resulting Stanza



<message to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='hecate@shakespeare.lit'/>

    <invite to='bard@shakespeare.lit'/>

  </x>

</message>

      



The URI may also include a password:



Example 189. Invite Action With Password: IRI/URI



xmpp:darkcave@macbeth.shakespeare.lit?invite;jid=hecate@shakespeare.lit;password=cauldronburn

      



If the joining user is not yet in the room, the application MUST send two stanzas: the first to join the room and the second to invite the other individual. If the joining user is in the room already, the application shall send only the invitation stanza.



Example 190. Invite Action With Password: Resulting Stanza(s)



<presence to='darkcave@macbeth.shakespeare.lit/thirdwitch'>

  <x xmlns='http://jabber.org/protocol/muc'/>

</presence>



<message to='darkcave@macbeth.shakespeare.lit'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='hecate@shakespeare.lit'>

      <password>cauldronburn</password>

    </invite>

  </x>

</message>

      





The following submission registers the "invite" querytype.



<querytype>

  <name>invite</name>

  <proto>http://jabber.org/protocol/muc</proto>

  <desc>enables simultaneously joining a groupchat room and inviting others</desc>

  <doc>XEP-0045</doc>

  <keys>

    <key>

      <name>jid</name>

      <desc>the Jabber ID of the invitee</desc>

    </key>

    <key>

      <name>password</name>

      <desc>the password required to enter a multi-user chat room</desc>

    </key>

  </keys>

</querytype>

      



16. Business Rules

16.1 Addresses



In order to provide consistency regarding the addresses captured in room JIDs, Room IDs MUST match the Nodeprep profile of Stringprep and Room Nicknames MUST match the Resourceprep profile of Stringprep (both of these are defined in RFC 3920). Although not explicitly stated in RFC 3920, both the Room ID (node) and Room Nickname (resource) portions of a Room JID MUST be of non-zero length. In addition, a MUC service MUST NOT allow empty or invisible Room Nicknames (i.e., Room Nicknames that consist only of one or more space characters).

16.2 Message



   1.



      If an occupant wants to send a message to all other occupants, a MUC client MUST set the 'type' attribute to a value of "groupchat". A service MAY ignore messages that are improperly typed, or reject them with a <bad-request/> error.

   2.



      If a MUC service receives a message directed to the room or to a single occupant from a Jabber user who has a role of "none", the service MUST NOT deliver the message and SHOULD return the message to the sender with a <forbidden/> error.

   3.



      If a MUC service receives a message directed to a room that does not exist or is not yet unlocked, the service SHOULD return the message to the sender with an <item-not-found/> error.

   4.



      A MUC service SHOULD pass extended information (e.g., an XHTML version of the message body) through to occupants unchanged; however, a MUC service MAY disallow message specific extensions (see the Allowable Traffic section of this document).

   5.



      A MUC client MAY generate extensions that conform to the Message Events [29] or Chat State Notifications [30] specification; however, a MUC service MAY disallow these extensions (see the Allowable Traffic section of this document).



16.3 Presence



   1.



      A room MUST silently ignore unavailable presence received from a user who has a role of "none".

   2.



      Only the MUC service itself SHOULD generate extended presence information about roles, affiliations, full JIDs, or status codes qualified by the 'http://jabber.org/protocol/muc#user' namespace (based on information the service knows about occupants, e.g., roles, or as a result of actions taken by a moderator or room administrator). A client SHOULD NOT presume to generate such information. If a MUC service receives such extended presence information from an occupant, it MUST NOT reflect it to other occupants. (A client MAY generate extended presence information qualified by the 'http://jabber.org/protocol/muc#user' namespace in order to supply a password, but naturally this is not reflected to other occupants.)

   3.



      A MUC service SHOULD allow all other presence information to pass through, although it MAY choose to block extended presence information; see the Allowable Traffic section of this document.

   4.



      In order to appropriately inform occupants of room roles and affiliations, and to make it easier for Jabber clients to track the current state of all users in the room, MUC service implementations MUST provide extended presence information about roles and affiliations in all presence stanzas, including presence stanzas of type "unavailable" sent when a user exits the room for any reason.

   5.



      If a privilege is revoked, the service MUST note that by sending an <x/> element qualified by the 'http://jabber.org/protocol/muc#user' namespace and containing an <item/> child element with the 'role' and/or 'affiliation' attributes set to a value that indicates the loss of the relevant privilege. All future presence stanzas for the occupant MUST include the updated role and affiliation, until and unless they change again.

   6.



      A MUC service MUST send extended presence to a client even if the client did not send an empty <x/> element qualified by the 'http://jabber.org/protocol/muc' namespace on entering the room; naturally, a client MUST ignore such information if it does not understand it (in accordance with RFC 3920).

   7.



      Extended presence about roles and affiliations sent in the muc#user namespace MUST include the full JID (not the bare JID) as the value of the 'jid' attribute.

   8.



      A client MAY send a custom exit message if desired (as is often done in IRC channels) by including a <status/> element in the presence stanza of type "unavailable" sent when exiting a room.



16.4 IQ



   1.



      If an occupant wants to send an IQ stanza to another user in a non-anonymous room, the sender SHOULD send the request directly to the recipient's bare JID or full JID, rather than attempting to send the request through the room (i.e., via the recipient's room JID).

   2.



      If an occupant wants to send an IQ stanza to another user in a semi-anonymous room, the sender can direct the stanza to the recipient's room JID and the service MAY forward the stanza to the recipient's real JID. However, a MUC service MUST NOT reveal the sender's real JID to the recipient at any time, nor reveal the recipient's real JID to the sender.

   3.



      A MUC client MUST send only the 'affiliation' attribute or the 'role' attribute in the <item/> element contained within an IQ set qualified by the 'http://jabber.org/protocol/muc#admin' namespace; if a moderator, admin, or owner attempts to modify both the affiliation and role of the same item in the same IQ set, the service MUST return a <bad-request/> error to the sender. However, a MUC service MAY modify a role based on a change to an affiliation and thus MAY send presence updates that include both a modified role and a modified affiliation.

   4.



      In IQ sets regarding roles, a MUC client MUST include the 'nick' attribute only; in IQ results regarding roles, a MUC service MUST include the 'nick', 'role', 'affiliation', and 'jid' attributes (with the value of the latter set to the user's full JID).

   5.



      In IQ sets regarding affiliations, a MUC client MUST include the 'jid' attribute only (with the value set to the bare JID); in IQ results regarding affiliations, a MUC service MUST NOT include the 'role' attribute, MUST include the 'affiliation' attribute and the 'jid' attribute (with the value set to the bare JID), and SHOULD include the 'nick' attribute (except if the affiliation is "outcast", since outcasts SHOULD NOT have reserved nicknames).



17. Implementation Notes



The following guidelines may assist client and component developers in creating MUC implementations.

17.1 Services



   1.



      In handling messages sent by visitors in a moderated room, a MUC service MAY queue each message for approval by a moderator and MAY inform the sender that the message is being held for approval; however, such behavior is OPTIONAL, and definition of a message approval protocol (e.g., using Data Forms as defined in XEP-0004) is out of scope for this document.

   2.



      It is common for MUC services to provide in-room messages when certain events occur, such as when the subject changes, when an occupant enters or exits, or when a room is destroyed. Such messages are entirely OPTIONAL and are left up to the implementation or deployment, but if used MUST be messages of type "groupchat" sent from the room JID itself (<room@service>) rather than a specific occupant (<room@service/nick>). However, in general it is preferable for the receiving client to generate such messages based on events in the room (e.g., user entrances and exits) as well as specific status codes provided in MUC; this will help ensure correct localization of such messages.

   3.



      Out of courtesy, a MUC service MAY send an out-of-room <message/> to an occupant who is kicked or banned, and MAY broadcast an in-room <message/> to all remaining occupants informing them that the occupant has been kicked or banned from the room. However, such messages are OPTIONAL, and indeed are unnecessary since the information required for a receiving client to generate such messages is communicated in the presence stanzas (specifically the status codes) sent by a MUC service.

   4.



      Out of courtesy, a MUC service MAY send an out-of-room <message/> if a user's affiliation changes while the user is not in the room; the message SHOULD be sent from the room to the user's bare JID, MAY contain a <body/> element describing the affiliation change, and MUST contain a status code of 101.

   5.



      There is no requirement that a MUC service shall provide special treatment for users of the older "groupchat 1.0" protocol, such as messages that contain equivalents to the extended presence information that is qualified by the 'http://jabber.org/protocol/muc#user' namespace.

   6.



      Room types MAY be configured in any combination. A MUC service MAY support or allow any desired room types or combinations thereof.

   7.



      A MUC service MAY limit the number of configuration options presented to an owner after initial configuration has been completed, e.g. because certain options cannot take effect without restarting the service.

   8.



      A MUC service MAY provide an interface to room creation and configuration (e.g., in the form of a special Jabber user or a Web page), so that the ostensible room owner is actually the application instead of a human user.

   9.



      A MUC service MAY choose to make available a special in-room resource that provides an interface to administrative functionality (e.g., a "user" named "ChatBot"), which occupants could interact with directly, thus enabling admins to type '/command parameter' in a private message to that "user". Obviously this kind of implementation would require the service to add a 'ChatBot' user to the room when it is created, and to prevent any occupant from having the nickname 'ChatBot' in the room. This might be difficult to ensure in some implementations or deployments. In any case, any such interface is OPTIONAL.

  10.



      A MUC service SHOULD remove a user if the service receives a delivery-related error in relation to a stanza it has previously sent to the user (remote server unreachable, user not found, etc.).

  11.



      A MUC service MAY choose to discard extended presence information that is attached to a <presence/> stanza before reflecting the presence change to the occupants of a room. That is, an implementation MAY choose to reflect only the <show/>, <status/>, and <priority/> child elements of the presence element as specified in the XML schema for the 'jabber:client' namespace, with the result that presence "changes" in extended namespaces (e.g., gabber:x:music:info) are not passed through to occupants. If a service prohibits certain extended namespaces, it SHOULD provide a description of allowable traffic at the well-known Service Discovery node 'http://jabber.org/protocol/muc#traffic' as described in the Allowable Traffic section of this document.

  12.



      A MUC service MAY choose to discard extended information attached to <message/> stanzas before reflecting the message to the occupants of a room. An example of such extended information is the lightweight text markup specified by XHTML-IM [31]. If a service prohibits certain extended namespaces, it SHOULD provide a description of allowable traffic at the well-known Service Discovery node 'http://jabber.org/protocol/muc#traffic' as described in the Allowable Traffic section of this document.

  13.



      A MUC service MAY choose to "lock down" room nicknames (e.g., hardcoding the room nickname to the bare JID of the occupant). If so, the service MUST treat the locked down nickname as a reserved room nickname and MUST support the protocol specified in the Discovering Reserved Room Nickname section of this document.



17.1.1 Allowable Traffic



As noted, a service (more precisely, a properly-configured room) MAY discard some or all extended namespaces attached to <message/> and <presence/> stanzas that are intended for reflection from the sender through the room to all of the room occupants. If the room does so, it SHOULD enable senders to discover the list of allowable extensions by sending a disco#info query to the well-known Service Discovery node 'http://jabber.org/protocol/muc#traffic', returning one <feature/> element for each namespace supported in the result. If the room does not allow any extended namespaces, it MUST return an empty query as specified in XEP-0030. If the room does not support the "#traffic" node, it MUST return a <feature-not-implemented/> error in response to queries sent to the 'http://jabber.org/protocol/muc#traffic' node.



The following example shows a room that allows the 'http://jabber.org/protocol/xhtml-im' and 'http://jabber.org/protocol/rosterx' namespaces only, but no other extended namespaces.



Example 191. User Queries Service Regarding Allowable Namespaces



<iq from='wiccarocks@shakespeare.lit/laptop'

    to='heath@macbeth.shakespeare.lit'

    id='allow1'

    type='get'>

  <query xmlns='http://jabber.org/protocol/disco#info'

         node='http://jabber.org/protocol/muc#traffic'/>

</iq>

      



Example 192. Service Returns Allowable Namespaces



<iq from='heath@macbeth.shakespeare.lit'

    to='wiccarocks@shakespeare.lit/laptop'

    id='allow1'

    type='result'>

  <query xmlns='http://jabber.org/protocol/disco#info'

         node='http://jabber.org/protocol/muc#traffic'>

    <feature var='http://jabber.org/protocol/xhtml-im'/>

    <feature var='http://jabber.org/protocol/rosterx'/>

  </query>

</iq>

      



If a service does not discard any namespaces or does not implement this feature, it MUST return a <service-unavailable/> error:



Example 193. Service Returns Service Unavailable



<iq from='heath@macbeth.shakespeare.lit'

    to='wiccarocks@shakespeare.lit/laptop'

    id='allow1'

    type='error'>

  <query xmlns='http://jabber.org/protocol/disco#info'

         node='http://jabber.org/protocol/muc#traffic'/>

  <error code='503' type='cancel'>

    <service-unavailable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>

  </error>

</iq>

      



17.2 Clients



   1.



      Jabber clients MAY present room roles by showing ad-hoc groups for each role within a room roster. This will enable occupants to clearly visualize which occupants are moderators, participants, and visitors. However, such a representation is OPTIONAL.

   2.



      Jabber clients MAY implement a variety of interface styles that provide "shortcuts" to functionality such as changing one's nickname, kicking or banning users, discovering an occupant's full JID, or changing the subject. One option consists of IRC-style commands such as '/nick', '/kick', '/ban', and '/whois'; another is to enable a user to right-click items in a room roster. All such interface styles are OPTIONAL. However, for convenience, a mapping of IRC commands to MUC protocols is provided below.



17.2.1 IRC Command Mapping



Internet Relay Chat clients use a number of common "shortcut" commands that begin with a forward slash, such as '/nick' and '/ban'. The following table provides a mapping of IRC-style commands to MUC protocols, for use by Jabber clients that wish to support such functionality.



Table 9: IRC Command Mapping

Command 	Function 	MUC protocol

/ban <roomnick> [comment] 	bans user with that roomnick from this room (client translates roomnick to bare JID) 	



<iq id='someid'

    to='room@service'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item affiliation='outcast'

          jid='bare-jid-of-user'>

      <reason>comment</reason>

    </item>

  </query>

</iq>

          



/invite <jid> [comment] 	invites user with that JID to this room 	



<message to='room@service'>

  <x xmlns='http://jabber.org/protocol/muc#user'>

    <invite to='jid'>

      <reason>comment</reason>

    </invite>

  </x>

</message>

          



/join <roomname> [pass] 	joins room on this service (roomnick is same as nick in this room) 	



<presence to='room@service/nick'>



  <x xmlns='http://jabber.org/protocol/muc#user'>

    <password>pass</password>

  </x>

</presence>

          



/kick <roomnick> [comment] 	kicks user with that roomnick from this room 	



<iq id='someid'

    to='room@service'

    type='set'>

  <query xmlns='http://jabber.org/protocol/muc#admin'>

    <item nick='roomnick' role='none'>

      <reason>comment</reason>

    </item>

  </query>

</iq>

          



/msg <roomnick> <foo> 	sends private message "foo" to roomnick 	



<message to='room@service/nick' type='chat'>

  <body>foo</body>

</message>

          



/nick <newnick> 	changes nick in this room to "newnick" 	



<presence to='room@service/newnick'/>

          



/part [comment] 	exits this room (some IRC clients also support /leave) 	



<presence to='room@service/nick'

          type='unavailable'>

  <status>comment</status>

</presence>

          



/topic <foo> 	changes subject of this room to "foo" 	



<message to='room@service' type='groupchat'>

  <subject>foo</subject>

</message>

          



Note: Because MUC roomnicks follow the Resourceprep profile of stringprep, they are allowed to contain a space character, whereas IRC nicknames do not. Although a given client MAY support quotation characters for this purpose (resulting in commands such as '/ban "king lear" insanity is no defense'), most common quotation characters (such as " and ') are also allowed by Resourceprep, thus leading to added complexity and potential problems with quotation of roomnicks that contain both spaces and quotation characters. Therefore it is NOT RECOMMENDED for Jabber clients to support IRC-style shortcut commands with roomnicks that contain space characters.



Note: Many Jabber clients also implement a '/me ' command, where the command is followed by a verb or verb phrase (e.g., '/me laughs'). This command does not result in any MUC or IRC protocol action and is therefore not shown in the foregoing table. Instead, the message is sent as-is (e.g., <body>/me laughs</body>) and the receiving client performs string-matching on the character data of the <body/> element to determine if the message begins with the string '/me '; if it does the receiving client will show the message in a special format, usually italicized text sometimes prepended by the "*" character:



* stpeter laughs

18. XML Schemas

18.1 http://jabber.org/protocol/muc



<?xml version='1.0' encoding='UTF-8'?>



<xs:schema

    xmlns:xs='http://www.w3.org/2001/XMLSchema'

    targetNamespace='http://jabber.org/protocol/muc'

    xmlns='http://jabber.org/protocol/muc'

    elementFormDefault='qualified'>



  <xs:annotation>

    <xs:documentation>

      The protocol documented by this schema is defined in

      XEP-0045: http://www.xmpp.org/extensions/xep-0045.html

    </xs:documentation>

  </xs:annotation>



  <xs:element name='x'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='history' minOccurs='0'/>

        <xs:element name='password' type='xs:string' minOccurs='0'/>

      </xs:sequence>

    </xs:complexType>

  </xs:element>



  <xs:element name='history'>

    <xs:complexType>

      <xs:simpleContent>

        <xs:extension base='empty'>

          <xs:attribute name='maxchars' type='xs:int' use='optional'/>

          <xs:attribute name='maxstanzas' type='xs:int' use='optional'/>

          <xs:attribute name='seconds' type='xs:int' use='optional'/>

          <xs:attribute name='since' type='xs:dateTime' use='optional'/>

        </xs:extension>

      </xs:simpleContent>

    </xs:complexType>

  </xs:element>



  <xs:simpleType name='empty'>

    <xs:restriction base='xs:string'>

      <xs:enumeration value=''/>

    </xs:restriction>

  </xs:simpleType>



</xs:schema>

    



18.2 http://jabber.org/protocol/muc#user



<?xml version='1.0' encoding='UTF-8'?>



<xs:schema

    xmlns:xs='http://www.w3.org/2001/XMLSchema'

    targetNamespace='http://jabber.org/protocol/muc#user'

    xmlns='http://jabber.org/protocol/muc#user'

    elementFormDefault='qualified'>



  <xs:annotation>

    <xs:documentation>

      The protocol documented by this schema is defined in

      XEP-0045: http://www.xmpp.org/extensions/xep-0045.html

    </xs:documentation>

  </xs:annotation>



  <xs:element name='x'>

    <xs:complexType>

      <xs:choice minOccurs='0' maxOccurs='unbounded'>

        <xs:element ref='decline' minOccurs='0'/>

        <xs:element ref='destroy' minOccurs='0'/>

        <xs:element ref='invite' minOccurs='0' maxOccurs='unbounded'/>

        <xs:element ref='item' minOccurs='0'/>

        <xs:element name='password' type='xs:string' minOccurs='0'/>

        <xs:element ref='status' minOccurs='0'/>

      </xs:choice>

    </xs:complexType>

  </xs:element>



  <xs:element name='decline'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='reason' minOccurs='0'/>

      </xs:sequence>

      <xs:attribute name='from' type='xs:string' use='optional'/>

      <xs:attribute name='to' type='xs:string' use='optional'/>

    </xs:complexType>

  </xs:element>



  <xs:element name='destroy'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='reason' minOccurs='0'/>

      </xs:sequence>

      <xs:attribute name='jid' type='xs:string' use='optional'/>

    </xs:complexType>

  </xs:element>



  <xs:element name='invite'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='reason' minOccurs='0'/>

      </xs:sequence>

      <xs:attribute name='from' type='xs:string' use='optional'/>

      <xs:attribute name='to' type='xs:string' use='optional'/>

    </xs:complexType>

  </xs:element>



  <xs:element name='item'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='actor' minOccurs='0'/>

        <xs:element ref='reason' minOccurs='0'/>

        <xs:element name='continue' type='empty' minOccurs='0'/>

      </xs:sequence>

      <xs:attribute name='affiliation' use='optional'>

        <xs:simpleType>

          <xs:restriction base='xs:NCName'>

            <xs:enumeration value='admin'/>

            <xs:enumeration value='member'/>

            <xs:enumeration value='none'/>

            <xs:enumeration value='outcast'/>

            <xs:enumeration value='owner'/>

          </xs:restriction>

        </xs:simpleType>

      </xs:attribute>

      <xs:attribute name='jid' type='xs:string' use='optional'/>

      <xs:attribute name='nick' type='xs:string' use='optional'/>

      <xs:attribute name='role' use='optional'>

        <xs:simpleType>

          <xs:restriction base='xs:NCName'>

            <xs:enumeration value='moderator'/>

            <xs:enumeration value='none'/>

            <xs:enumeration value='participant'/>

            <xs:enumeration value='visitor'/>

          </xs:restriction>

        </xs:simpleType>

      </xs:attribute>

    </xs:complexType>

  </xs:element>



  <xs:element name='actor'>

    <xs:complexType>

      <xs:simpleContent>

        <xs:extension base='empty'>

          <xs:attribute name='jid' type='xs:string' use='required'/>

        </xs:extension>

      </xs:simpleContent>

    </xs:complexType>

  </xs:element>



  <xs:element name='status'>

    <xs:complexType>

      <xs:attribute name='code' use='required'>

        <xs:simpleType>

          <xs:restriction base='xs:int'>

            <xs:length value='3'/>

          </xs:restriction>

        </xs:simpleType>

      </xs:attribute>

    </xs:complexType>

  </xs:element>



  <xs:element name='reason' type='xs:string'/>



  <xs:simpleType name='empty'>

    <xs:restriction base='xs:string'>

      <xs:enumeration value=''/>

    </xs:restriction>

  </xs:simpleType>



</xs:schema>

    



18.3 http://jabber.org/protocol/muc#admin



<?xml version='1.0' encoding='UTF-8'?>



<xs:schema

    xmlns:xs='http://www.w3.org/2001/XMLSchema'

    targetNamespace='http://jabber.org/protocol/muc#admin'

    xmlns='http://jabber.org/protocol/muc#admin'

    elementFormDefault='qualified'>



  <xs:annotation>

    <xs:documentation>

      The protocol documented by this schema is defined in

      XEP-0045: http://www.xmpp.org/extensions/xep-0045.html

    </xs:documentation>

  </xs:annotation>



  <xs:element name='query'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='item' maxOccurs='unbounded'/>

      </xs:sequence>

    </xs:complexType>

  </xs:element>



  <xs:element name='item'>

    <xs:complexType>

      <xs:sequence>

        <xs:element ref='actor' minOccurs='0'/>

        <xs:element ref='reason' minOccurs='0'/>

      </xs:sequence>

      <xs:attribute name='affiliation' use='optional'>

        <xs:simpleType>

          <xs:restriction base='xs:NCName'>

            <xs:enumeration value='admin'/>

            <xs:enumeration value='member'/>

            <xs:enumeration value='none'/>

            <xs:enumeration value='outcast'/>

            <xs:enumeration value='owner'/>

          </xs:restriction>

        </xs:simpleType>

      </xs:attribute>

      <xs:attribute name='jid' type='xs:string' use='optional'/>

      <xs:attribute name='nick' type='xs:string' use='optional'/>

      <xs:attribute name='role' use='optional'>

        <xs:simpleType>

          <xs:restriction base='xs:NCName'>

            <xs:enumeration value='moderator'/>

            <xs:enumeration value='none'/>

            <xs:enumeration value='participant'/>

            <xs:enumeration value='visitor'/>

          </xs:restriction>

        </xs:simpleType>

      </xs:attribute>

    </xs:complexType>

  </xs:element>



  <xs:element name='actor'>

    <xs:complexType>

      <xs:simpleContent>

        <xs:extension base='empty'>

          <xs:attribute name='jid' type='xs:string' use='required'/>

        </xs:extension>

      </xs:simpleContent>

    </xs:complexType>

  </xs:element>



  <xs:element name='reason' type='xs:string'/>



  <xs:simpleType name='empty'>

    <xs:restriction base='xs:string'>

      <xs:enumeration value=''/>

    </xs:restriction>

  </xs:simpleType>



</xs:schema>

    



18.4 http://jabber.org/protocol/muc#owner



<?xml version='1.0' encoding='UTF-8'?>



<xs:schema

    xmlns:xs='http://www.w3.org/2001/XMLSchema'

    targetNamespace='http://jabber.org/protocol/muc#owner'

    xmlns='http://jabber.org/protocol/muc#owner'

    elementFormDefault='qualified'>



  <xs:annotation>

    <xs:documentation>

      The protocol documented by this schema is defined in

      XEP-0045: http://www.xmpp.org/extensions/xep-0045.html

    </xs:documentation>

  </xs:annotation>



  <xs:import 

      namespace='jabber:x:data'

      schemaLocation='http://www.xmpp.org/schemas/x-data.xsd'/>



  <xs:element name='query'>

    <xs:complexType>

      <xs:choice xmlns:xdata='jabber:x:data' minOccurs='0'>

        <xs:element ref='xdata:x'/>

        <xs:element ref='destroy'/>

      </xs:choice>

    </xs:complexType>

  </xs:element>



  <xs:element name='destroy'>

    <xs:complexType>

      <xs:sequence>

        <xs:element name='password' type='xs:string' minOccurs='0'/>

        <xs:element name='reason' type='xs:string' minOccurs='0'/>

      </xs:sequence>

      <xs:attribute name='jid' type='xs:string' use='optional'/>

    </xs:complexType>

  </xs:element>



  <xs:simpleType name='empty'>

    <xs:restriction base='xs:string'>

      <xs:enumeration value=''/>

    </xs:restriction>

  </xs:simpleType>



</xs:schema>

    



18.5 http://jabber.org/protocol/muc#unique



<?xml version='1.0' encoding='UTF-8'?>



<xs:schema

    xmlns:xs='http://www.w3.org/2001/XMLSchema'

    targetNamespace='http://jabber.org/protocol/muc#unique'

    xmlns='http://jabber.org/protocol/muc#unique'

    elementFormDefault='qualified'>



  <xs:annotation>

    <xs:documentation>

      The protocol documented by this schema is defined in

      XEP-0045: http://www.xmpp.org/extensions/xep-0045.html

    </xs:documentation>

  </xs:annotation>



  <xs:element name='unique' type='xs:string'/>



</xs:schema>

    



19. Acknowledgements



The author would like to thank the following individuals for their many helpful comments on various drafts of this proposal: David Sutton, Peter Millard, Joe Hildebrand, Craig Kaes, Alexey Shchepin, David Waite, Jean-Louis Seguineau, Jacek Konieczny, Gaston Dombiak, and many others in the jdev@conference.jabber.org conference room and on the Standards mailing list.

Notes



1. RFC 1459: Internet Relay Chat <http://tools.ietf.org/html/rfc1459>.



2. RFC 2810: Internet Relay Chat: Architecture <http://tools.ietf.org/html/rfc2810>.



3. RFC 2811: Internet Relay Chat: Channel Management <http://tools.ietf.org/html/rfc2811>.



4. RFC 2812: Internet Relay Chat: Client Protocol <http://tools.ietf.org/html/rfc2812>.



5. RFC 2813: Internet Relay Chat: Server Protocol <http://tools.ietf.org/html/rfc2813>.



6. http://www.jabber.org/protocol/groupchat.html



7. XEP-0030: Service Discovery <http://www.xmpp.org/extensions/xep-0030.html>.



8. XEP-0128: Service Discovery Extensions <http://www.xmpp.org/extensions/xep-0128.html>.



9. RFC 3920: Extensible Messaging and Presence Protocol (XMPP): Core <http://tools.ietf.org/html/rfc3920>.



10. XEP-0203: Delayed Delivery <http://www.xmpp.org/extensions/xep-0203.html>.



11. XEP-0091: Delayed Delivery <http://www.xmpp.org/extensions/xep-0091.html>.



12. XEP-0082: XMPP Date and Time Profiles <http://www.xmpp.org/extensions/xep-0082.html>.



13. RFC 3921: Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence <http://tools.ietf.org/html/rfc3921>.



14. XEP-0077: In-Band Registration <http://www.xmpp.org/extensions/xep-0077.html>.



15. XEP-0004: Data Forms <http://www.xmpp.org/extensions/xep-0004.html>.



16. Some commentors have complained that this opens room owners and administrators up to potential abuse; unfortunately, with great power comes great responsibility.



17. XEP-0133: Service Administration <http://www.xmpp.org/extensions/xep-0133.html>.



18. XEP-0050: Ad-Hoc Commands <http://www.xmpp.org/extensions/xep-0050.html>.



19. XEP-0060: Publish-Subscribe <http://www.xmpp.org/extensions/xep-0060.html>.



20. This is different from the behavior of room configuration, wherein the 'muc#roomconfig_roomowners' field specifies the full list of room owners, not the delta.



21. This is different from the behavior of room configuration, wherein the 'muc#roomconfig_roomadmins' field specifies the full list of room admins, not the delta.



22. XEP-0086: Error Condition Mappings <http://www.xmpp.org/extensions/xep-0086.html>.



23. RFC 2616: Hypertext Transport Protocol -- HTTP/1.1 <http://tools.ietf.org/html/rfc2616>.



24. RFC 1893: Enhanced Mail System Status Codes <http://tools.ietf.org/html/rfc1893>.



25. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.



26. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://www.xmpp.org/registrar/>.



27. XEP-0068: Field Data Standardization for Data Forms <http://www.xmpp.org/extensions/xep-0068.html>.



28. XEP-0147: XMPP URI Query Components <http://www.xmpp.org/extensions/xep-0147.html>.



29. XEP-0022: Message Events <http://www.xmpp.org/extensions/xep-0022.html>.



30. XEP-0085: Chat State Notifications <http://www.xmpp.org/extensions/xep-0085.html>.



31. XEP-0071: XHTML-IM <http://www.xmpp.org/extensions/xep-0071.html>.

Revision History

Version 1.22 (2007-04-10)



Updated delayed delivery reference to reflect advancement of XEP-0203 to Draft and deprecation of XEP-0091.

(psa)

Version 1.21 (2006-09-13)



    * Clarified that inclusion of MUC extension in room join/create request triggers Data Forms flow but that absence of MUC extension leads to automatic room creation for backwards compatibility with older groupchat 1.0 protocol.

    * Specified use of <not-acceptable/> error on nickname change if nicks are locked down.

    * Required clients to discover room configuration prior to entering room and specified related security considerations, including use of privacy-related status codes 170, 171, 172, 173, and 174.

    * Specified use of <not-acceptable/> error if room configuration options cannot be processed or violate service policies.

    * Made explicit that roomnicks must not consist only of spaces.

    * Moved all service discovery use cases into dedicated section.

    * Changed urn:xmpp:delay support from SHOULD to MUST.

    * Clarified that _whois room configuration option specifies room type.

    * Defined XEP-0128 room information fields for discussion logs, associated pubsub node, and contact JID.

    * Specified that changing role to moderator upon affiliation change to admin or owner is recommended, not required.

    * Added internationalization consideration about localization of field labels for various data forms.

    * Specified that implementations may persist roles across visits and should do so for moderated rooms.

    * Added protocol and service discovery feature for requesting a unique room name prior to room creation.

    * Further clarified nature of reserved room nicknames and nickname lockdown.

    * Defined data forms for requesting voice and approving voice requests.

    * Added multiple invitee example for XMPP URI.

    * Clarified order of presence, discussion history, etc.

    * Added status codes for occupant's own roomnick, service-modified roomnick, and warning that room discussion is publicly logged.

    * Clarified privacy and anonymity considerations regarding room logging and non-anonymous rooms.



(psa)

Version 1.20 (2005-09-08)



Harmonized ability to kick and ban users, and clarified that a user cannot be kicked or banned by a moderator or admin with a lower affiliation.

(psa)

Version 1.19 (2005-04-21)



Specified how to send multiple invitations simultaneously; corrected some errors regarding consistency of affiliation state changes; changed message events prohibition from MUST NOT to SHOULD NOT; corrected error handling related to the #traffic disco node; allowed <password/> as a child of <destroy/>; changed max users error from <not-allowed/> to <service-unavailable/>; specified that the maxchars attribute counts characters in complete XML stanzas; added disco features for FORM_TYPEs; defined registry for status codes; split Create Instant Room into separate use case for protocol compliance purposes; adjusted XML schemas to reflect the foregoing changes; re-wrote the introduction; clarified small textual matters throughout.

(psa)

Version 1.18 (2004-11-02)



Corrected several errors in the affiliation state chart and in the examples (wrong FORM_TYPE values); mentioned /me command.

(psa)

Version 1.17 (2004-10-04)



Added text about allowable extension namespaces and related service discovery mechanisms; specified well-known service discovery nodes; added conformance terms to clarify some descriptions; modified affiliation state chart to allow more flexible state changes; per list dicussion, added ability to convert a one-to-one chat into a conference, including sending of history; specified error to use when max users limit is reached; specified form for admin approval of user registration requests and modified FORM_TYPE from http://jabber.org/protocol/muc#user to http://jabber.org/protocol/muc#register; modified FORM_TYPE for room configuration from http://jabber.org/protocol/muc#owner to http://jabber.org/protocol/muc#roomconfig.

(psa)

Version 1.16 (2004-06-30)



Added example and registry submission for service discovery extension.

(psa)

Version 1.15 (2004-06-24)



Removed jabber:iq:browse references; clarified order of presence stanzas sent to new occupant on entering room; specified format of in-room messages (type='groupchat', from='room@service'); clarified allowable attributes in various list-related operations; made admin/owner revocation text and examples consistent with state chart; clarified ownership revocation conflict scenarios; changed the 'muc#roomconfig_inviteonly' field to 'muc#roomconfig_membersonly'; changed attribute order in examples to match XML canonicalization rules; corrected several errors in the schemas.

(psa)

Version 1.14 (2004-05-03)



Corrected discovery of registered roomnicks; added note about error to return if nicks are locked down.

(psa)

Version 1.13 (2004-03-31)



Fixed an error in the muc#user schema.

(psa)

Version 1.12 (2004-03-01)



Corrected a few errors in the examples; added IQ results in order to clarify workflows.

(psa)

Version 1.11 (2004-02-05)



Clarified JID matching rules (same as for privacy lists in XMPP IM).

(psa)

Version 1.10 (2004-01-07)



Added XMPP error handling; fully specified all conformance terms.

(psa)

Version 1.9 (2003-12-14)



Removed protocol for requesting voice in a moderated room (should be performed using Ad-Hoc Commands).

(psa)

Version 1.8 (2003-12-04)



Added protocol for requesting voice in a moderated room; added (informational) mapping of IRC commands to MUC protocols.

(psa)

Version 1.7 (2003-10-21)



Added room configuration option for restricting presence broadcast to certain roles.

(psa)

Version 1.6 (2003-10-03)



Added history management protocol on entering a room.

(psa)

Version 1.5 (2003-09-11)



Specified that ban occurs by JID, not roomnick; allowed privileged users to send messages to the room even if not present in the room; added note that service should remove occupant if a delivery-related stanza error occurs; enabled user to disco the room in order to discover registered roomnick; specified that "banning" by domain or regex is a service-level configuration matter and therefore out of scope for MUC; specified that role should be decremented as appropriate if affiliation is lowered; added some clarifying text to room creation workflow; added implementation note about sending an out-of-band message if a user's affiliation changes while the user is not in the room; fixed stringprep references (room nicks use Resourceprep); clarified relationship between Room ID (i.e., node identifier of Room JID, which may be opaque) and natural-language Room Name; specified Field Standardization profile per XEP-0068; defined XMPP Registrar submissions; added schema locations.

(psa)

Version 1.4 (2003-02-16)



Added XML schemas.

(psa)

Version 1.3 (2003-02-11)



Added reference to nodeprep Internet-Draft.

(psa)

Version 1.2 (2003-01-30)



Commented out revision history prior to version 1.0 (too long); clarified business rules regarding when nicks, full JIDs, and bare JIDs are used in reference to roles and affiliations; consistently specified that extended presence information in the muc#user namespace must include the full JID as the value of the 'jid' attribute in all cases; cleaned up text and examples throughout; added open issue regarding syntax of room nicknames.

(psa)

Version 1.1 (2002-12-16)



Added protocol for declining an invitation; replaced <created/> element with status code 201; modified the destroy room protocol so that <destroy/> is a child of <query/>; clarified usage of 'nick' attribute when adding members; prohibited use of message events.

(psa)

Version 1.0 (2002-11-21)



Per a vote of the Jabber Council, revision 0.23 was advanced to Draft on 2002-11-21. (For earlier revision history, refer to XML source.)

(psa)

Version 0.23 (2002-11-06)



Added examples for disco#items queries sent to a room; prohibited 'type' attribute on invite messages sent from client to room; added dependencies on browse and disco; changed 'room user' to 'occupant'; fixed many small errors throughout.

(psa)

Version 0.22 (2002-11-04)



Added example for disco#items; added support for cancellation of room configuration using type='cancel' from XEP-0004; noted 403 error for invites sent by non-admins in members-only room.

(psa)

Version 0.21 (2002-11-01)



Clarified several small ambiguities; made <body/> optional on invites sent from the service to the invitee; added error scenarios for changing nickname and for destroying the room; specified that the service must return the full member list for a members-only room (not only the members in the room); updated the disco examples to track protocol changes.

(psa)

Version 0.20 (2002-10-29)



Specified that messages sent to change the room subject must be of type "groupchat"; updated the legal notice to conform to the XSF IPR policy.

(psa)

Version 0.19 (2002-10-28)



Added ability to create an instant room within MUC (not by using gc-1.0 protocol); cleaned up disco examples.

(psa)

Version 0.18 (2002-10-27)



Added experimental support for disco; added sections for security, IANA, and JANA considerations; corrected typographical errors; cleaned up some DocBook formatting.

(psa)

Version 0.17 (2002-10-23)



Added the optional <actor/> element (with 'jid' attribute) to <item/> elements inside presence stanzas of type "unavailable" that are sent to users who are kicked or banned, as well as within IQs for tracking purposes; reverted all list editing use cases (ban, voice, member, moderator, admin, owner) to use of MUC format rather than 'jabber:x:data' namespace; added several guidelines regarding generation and handling of XML stanzas; cleaned up the change room subject use case; changed several ambiguous uses of 'would', 'can', and 'will' to 'should', 'may', or 'must'; fixed several small errors in the text, examples, and DTDs.

(psa)

Version 0.16 (2002-10-20)



Added the <item/> element to presence stanzas of type "unavailable" in order to improve the tracking of user states in the room; consolidated <invitee/> and <invitor/> elements into an <invite/> element with 'from' and 'to' attributes; made <reason/> element always a child of <item/> or <invite/> in the muc#user namespace; moved the alternate room location in room destruction to a 'jid' attribute of the <alt/> element; further specified several error messages; disallowed simultaneous modifications of both affiliations and roles by a moderator or admin; added several more rules regarding handling of XML stanzas; added use cases for granting and revoking administrative privileges; adjusted DTD to track all changes.

(psa)

Version 0.15 (2002-10-18)



Fully incorporated the change to affiliations + roles; moved a number of admin use cases to a new section for moderator use cases; added participant use case for requesting membership; added admin use cases for adding members, removing members, granting and revoking moderator privileges, and modifying the moderator list; organized the sections in a more logical manner.

(psa)

Version 0.14 (2002-10-17)



Significantly modified the privileges model by distinguishing between in-room "roles" and long-lived "affiliations"; specified the privileges of the various roles and affiliations; included state transition charts for both roles and affiliations; removed use of MUC protocol for editing ban, voice, and admin lists (but not for the actions of banning users and granting/revoking voice); added delivery rule regarding IQ stanzas; changed kick so that the action is based on changing the role to "none".

(psa)

Version 0.13 (2002-10-16)



Corrected the change nickname examples (newnick sent on unavailable, no nick sent on available).

(psa)

Version 0.12 (2002-10-16)



Removed SHA1 passwords; specified that room shall add passwords on invitations to password-protected rooms (not supplied by invitor).

(psa)

Version 0.11 (2002-10-16)



Changed 'participant' to 'room user' and 'discussant' to 'participant'; clarified presence rule about client generation of extended presence information; added role of 'none'.

(psa)

Version 0.10 (2002-10-15)



Fixed extended presence on entering or creating a room (plain '...muc' with no fragment); harmonized #user with #admin regarding the use of the <item/> element and associated attributes (jid, nick, etc.), and added 'role' attribute; modified management of voice, ban, admin, and member lists to use <query/> wrapper and new <item/> structure; changed the 'member' role to 'discussant', added 'outcast' role for banned users, and added new 'member' role to enable management of member lists; changed invitation-only rooms to members-only rooms and made appropriate adjustments to apply member lists to both members-only rooms and open rooms; modified nickname change protocol slightly to send the old nickname in the unavailable presence and the new nickname in the available presence; removed prohibition on members-only rooms that are password-protected; removed the <query/> wrapper for the <destroy/> element; updated the DTDs.

(psa)

Version 0.9 (2002-10-13)



Added extended presence ('...#user') on entering a room for MUC clients; changed namespace on room creation request to '...#owner'; added a service discovery example using jabber:iq:browse; added information about discussion history; made small fixes to several examples; further defined the presence rules; transferred all implementation notes to a dedicated section; added a Terminology section.

(psa)

Version 0.8 (2002-10-10)



Made further changes to the room creation workflow (finally correct); removed feature discovery use case (this needs to be addressed by a real service discovery protocol!); added ability for room owners to edit the admin list; removed <body/> from invitations generated by the service; removed messages sent to kicked and banned users (handled by unavailable presence with status code); added a number of implementation notes; converted all examples to Shakespeare style.

(psa)

Version 0.7.6 (2002-10-09)



Fixed the room creation workflow; changed some terminology ("join" to "enter" and "leave" to "exit").

(psa)

Version 0.7.5 (2002-10-08)



Specified and improved the handling of invitation-only rooms. In particular, added the ability for room admins to edit the invitation list and added a configuration option that limits the ability to send invitations to room admins only.

(psa)

Version 0.7.4 (2002-10-07)



Changed namespaces from http://jabber.org/protocol/muc/owner etc. to http://jabber.org/protocol/muc#owner etc. per Jabber Council discussion.

(psa)

Version 0.7.3 (2002-10-07)



Changed namespaces to HTTP URIs; left role handling up to the implementation; further clarified presence rules.

(psa)

Version 0.7.2 (2002-10-06)



Disallowed kicking, banning, and revoking voice with respect to room admins and room owners; replaced <x/> with <query/> in the Discovering Room Features and Destroying a Room use cases; corrected some small errors and made many clarifications throughout.

(psa)

Version 0.7.1 (2002-10-04)



Removed <whois/> command (unnecessary since participants with appropriate privileges receive the full JID of all participants in presence stanzas); completed many small fixes throughout.

(psa)

Version 0.7 (2002-10-03)



More clearly delineated participant roles and defined the hierarchy thereof (owner, admin, member, visitor); replaced <voice/> element in extended presence with <item role='member'/>; changed initial room configuration to use IQ rather than message; adjusted presence rules (especially regarding extended presence information); cleaned up examples throughout; updated DTD to track changes.

(psa)

Version 0.6 (2002-09-21)



More clearly defined the scope; removed fully anonymous rooms; changed meaning of semi-anonymous rooms and of non-anonymous rooms; added mechanism for notification of full JIDs in non-anonymous rooms; replaced the <admin/> element in extended presence with a <role/> element (more extensible); changed room passwords to cleartext; added status codes for various messages received from the service; added lists of valid error and status codes associated with the 'http://jabber.org/protocol/muc#user' namespace; added a <reason/> element for invitations; made kick and ban reasons child elements rather than attributes; replaced stopgap feature discovery mechanism with jabber:iq:negotiate; added extended presence element to room creation request and clarified the room creation process; specified presence reflection rules; added method for destroying a room; adjusted DTDs to track all changes.

(psa)

Version 0.5.1 (2002-09-20)



Added DTDs; changed feature discovery to use <x/> element rather than query and made service response come in IQ result; fixed reference to JID spec; changed 'grant' to 'add' and 'revoke' to 'remove' for consistency in the item attributes; made several other small changes.

(psa)

Version 0.5 (2002-09-19)



Changed the kick, ban, and voice protocols; added a few more configuration options; specified the restrictions for roomnicks; and added a stopgap service discovery protocol.

(psa)

Version 0.4 (2002-09-18)



Changed all non-GC-1.0 use cases to jabber:gc:* namespaces or jabber:x:data; added use cases for ban list management and room moderation; added protocol for sending notice of admin and voice privileges in presence; cleaned up text and many examples.

(psa)

Version 0.3 (2002-09-17)



Changed admin use cases; cleaned up participant and owner use cases.

(psa)

Version 0.2 (2002-09-12)



Broke content out into three actors (participant, owner, and admin) and added more detail to owner and admin use cases.

(psa)

Version 0.1 (2002-09-09)



Initial version.

(psa)



END"

'''文档信息'''

系列: [[XMPP扩展]]

编号: 0045

发行者: [XMPP文档列表/XMPP标准基金会]

状态: 草案

类型: 标准跟踪

版本: 1.24

最后更新日期: 2008-07-16

批准机构: [XMPP文档列表/XMPP理事会]

依赖于: [[XMPP Core]], [[XMPP IM]], XEP-0004, XEP-0030, XEP-0068, XEP-0082, XEP-0128

上文: 无

下文: 无

简称: muc

muc名字空间的XML方案: <http://www.xmpp.org/schemas/muc.xsd>

muc#admin名字空间的XML方案: <http://www.xmpp.org/schemas/muc-admin.xsd>

muc#owner名字空间的XML方案: <http://www.xmpp.org/schemas/muc-owner.xsd>

muc#unique名字空间的XML方案: <http://www.xmpp.org/schemas/muc-unique.xsd>

muc#user名字空间的XML方案: <http://www.xmpp.org/schemas/muc-user.xsd>

注册项: <http://www.xmpp.org/registrar/muc.html>

Wiki页: <http://wiki.jabber.org/index.php/Multi-User Chat (XEP-0045)>

'''作者信息'''

:'''Peter Saint-Andre'''

:Email: [mailto:stpeter@jabber.org stpeter@jabber.org]

:JabberID: [xmpp:stpeter@jabber.org stpeter@jabber.org]

'''法律通告'''

'''版权'''

XMPP扩展协议的版权(1999-2008)归XMPP标准化基金会(XSF)所有.

'''权限'''

特此授权,费用全免,对任何获得本协议副本的人,对使用本协议没有限制,包括不限制在软件程序中实现本协议,不限制在网络服务中布署本协议,不限制拷贝,修改,合并,发行,翻译,分发,转授,或销售本协议的副本,被允许使用本协议做了以上工作的人士,应接受前述的版权声明和本许可通知并且必须包含在所有的副本或实质性部分的规格中.除非单独的许可，被重新分发的修改工作，不得含有关于作者，标题，编号，或出版者的规格的误导性资料，并不得宣称修改工作是由本文的作者，作者所属的任何组织或项目，或XMPP标准基金会签注。

'''免责声明''''

注意：本协议是提供的“原样”的基础，没有担保或任何形式的条件，明示或暗示，包括，但不限于任何担保或关于名称，非侵权性，适销性或适合作某一特定目的的条件.在任何情况XMPP标准基金会或作者不对此协议承担任何责任索赔，损害赔偿，或其他责任，无论是在一项行动的合同，侵权，或否则，所产生的，运出，或在他涉嫌与规格或执行，部署或以其它方式使用本协议. ##

'''责任限制'''

在任何情况下以及没有任何法律规定时，不论是侵权行为（包括疏忽），合同或其它方面，除非根据适用法律的要求（如蓄意和有严重疏忽行为）或同意以书面形式，XMPP标准基金会或任何作者不对本协议承担所造成的损失，包括任何直接，间接，特殊，偶发，或相应的损害赔偿的任何字符利用所产生的或不能使用的规格（包括但不限于善意的损失，停止作业，电脑失灵或故障，或任何和所有其他商业损害或损失） ，即使XMPP标准基金会或作者已被告知此类损害的可能性。

'''知识产权的一致性'''

XMPP扩展协议完全遵守XSF的知识产权策略(可在<http://www.xmpp.org/extensions/ipr-policy.shtml>找到副本或写信给XSF, P.O. Box 1641, Denver, CO 80201 USA). 

'''讨论地点'''

首选的讨论的地方是标准讨论邮件列表: <http://mail.jabber.org/mailman/listinfo/standards>.

勘误表发送到[mailto:editor@xmpp.org editor@xmpp.org]

'''XMPP 相关信息'''

XMPP 是由XSF(XMPP标准化基金会)按互联网标准程序贡献的,和 IETF的RFC 2026兼容的规范,包括 XMPP核心(RFC 3920)和 XMPP IM(RFC 3921).在本文中定义的任何协议,都是在互联网标准程序之外开发的,是扩展XMPP,而不是改变、发展和修改 XMPP本身.

'''一致性术语'''

本文中以下关键词的含义如 RFC 2119 所述: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".