xep-0245.xml

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE xep SYSTEM 'xep.dtd' [
  <!ENTITY % ents SYSTEM 'xep.ent'>
%ents;
]>
<?xml-stylesheet type='text/xsl' href='xep.xsl'?>
<xep>
<header>
  <title>The /me Command</title>
  <abstract>This specification defines recommended handling of the /me command in XMPP instant messaging clients.</abstract>
  &LEGALNOTICE;
  <number>0245</number>
  <status>Active</status>
  <type>Informational</type>
  <sig>Standards</sig>
  <approver>Council</approver>
  <dependencies>
    <spec>XMPP Core</spec>
    <spec>XMPP IM</spec>
  </dependencies>
  <supersedes/>
  <supersededby/>
  <shortname>N/A</shortname>
  &stpeter;
  <revision>
    <version>1.0</version>
    <date>2009-01-21</date>
    <initials>psa</initials>
    <remark><p>Per a vote of the XMPP Council, advanced specification to Active and changed type from Historical to Informational.</p></remark>
  </revision>
  <revision>
    <version>0.2</version>
    <date>2009-01-08</date>
    <initials>psa</initials>
    <remark><p>Clarified handling of XHTML-IM formatting; added security consideration for multi-user chat rooms.</p></remark>
  </revision>
  <revision>
    <version>0.1</version>
    <date>2008-06-18</date>
    <initials>psa</initials>
    <remark><p>Initial published version.</p></remark>
  </revision>
  <revision>
    <version>0.0.1</version>
    <date>2008-06-09</date>
    <initials>psa</initials>
    <remark><p>First draft.</p></remark>
  </revision>
</header>

<section1 topic='Introduction' anchor='intro'>
  <p>Many Jabber/XMPP instant messaging clients provide special processing and presentation of the string "/me " at the beginning of a message body. This specification describes the recommended handling of this "command".</p>
</section1>

<section1 topic='Recommended Handling' anchor='handling'>
  <p>The /me command <note>The string "/me " is usually pronounced "slash-me".</note> is a text string that enables a human user to type an action phrase and have it be presented in a special way within an instant messaging client.  The text string is followed by a verb or verb phrase, such as "/me laughs" or "/me is logging off now". This command does not result in the generation of any XMPP protocol. Instead, the command is sent as-is (e.g., &lt;body&gt;/me laughs&lt;/body&gt;) and the receiving client performs string-matching on the first four characters of the data included in the &BODY; element to determine if the message begins with the string "/me ". If the client finds a match, the receiving client will show the message with a special presentation. It is RECOMMENDED for the client to show the receiving client's understanding of the sender's user name, nickname, or handle <note>On the difference between user names, nicknames, and handles, see &xep0165; and &xep0172;.</note> followed by the verb phrase in italicized text, prepended by the "*" character.</p>
  <p>For example, imagine that the Greek god Atlas is in a chatroom with the other gods and types the following text in his IM client:</p>
  <example caption="A /me Command"><![CDATA[
/me shrugs in disgust
]]></example>
  <p>That text will be sent to all the occupants in the chatroom as follows:</p>
  <example caption="XMPP Stanza"><![CDATA[
<message from='olympians@chat.gods.lit/Atlas'
         to='olympians@chat.gods.lit'
         type='groupchat'>
  <body>/me shrugs in disgust</body>
</message>
]]></example>
  <p>Each recipient's client would then show the message with a special presentation, such as:</p>
  <example caption="Presentation of /me Command">
* Atlas shrugs in disgust
  </example>
  <p>If the receiving client does not find a match on the string "/me " in the first four characters of the message body, it SHOULD NOT present the text in a special way. For example, the following message bodies do not match:</p>
  <example caption="Some Non-Commands"><![CDATA[
<body>/meshrugs in disgust</body>

<body>/me's disgusted</body>

<body> /me shrugs in disgust</body>

<body>"/me shrugs in disgust"</body>

<body>* Atlas shrugs in disgust</body>

<body>Why did Atlas say "/me shrugs in disgust"?</body>
]]></example>
</section1>

<section1 topic='Integration With XHTML-IM' anchor='xhtml'>
  <p>&xep0071; describes a method for lightweight formatting of a message body using a subset of XHTML. For example, the stanza shown above might be formatted in the color green, as follows.</p>
  <example caption="XMPP Stanza With XHTML-IM"><![CDATA[
<message from='olympians@chat.gods.lit/Atlas'
         to='olympians@chat.gods.lit'
         type='groupchat'>
  <body>/me shrugs in disgust</body>
  <html xmlns='http://jabber.org/protocol/xhtml-im'>
    <body xmlns='http://www.w3.org/1999/xhtml'>
      <p style='color:green'>/me shrugs in disgust</p>
    </body>
  </html>
</message>
]]></example>
  <p>The XHTML-formatted version of the message MUST NOT modify the "/me " command string (e.g., in this case to something like "* Atlas shrugs in disgust") because the recipient might have a different user name, nickname, or handle on file for the sender.</p>
</section1>

<section1 topic='Accessibility Considerations' anchor='access'>
  <p>This specification describes the /me command in terms of visual presentation. A receiving client that presents messages aurally MAY modify its presentation of /me commands and SHOULD at a minimum transform the string "/me " into the user name, nickname, or handle of the sender.</p>
</section1>

<section1 topic='Security Considerations' anchor='security'>
  <p>&xep0045; rooms send XMPP presence stanzas when people leave and join the room, and receiving clients typically show these presence changes as the equivalent of in-room messages, such as the following transformation of a presence stanza of type unavailable:</p>
  <example caption="Presentation of In-Room Presence Notification">
*** Atlas has left the room
  </example>
  <p>A sender could attempt to spoof such a leave message by sending an XMPP groupchat message stanza whose body text is "/me has left the room". Although the presentation of presence joins and leaves is determined by the receiving client and therefore such a notification cannot be universally spoofed for all receivers, a client SHOULD differentiate between presence notifications and /me commands (e.g., with different colors and different prepended characters, such as several asterisks for presence notifications and one asterisk for /me commands).</p>
</section1>

<section1 topic='IANA Considerations' anchor='iana'>
  <p>This document requires no interaction with &IANA;.</p>
</section1>

<section1 topic='XMPP Registrar Considerations' anchor='registrar'>
  <p>This document requires no interaction with the &REGISTRAR;.</p>
</section1>

<section1 topic='Acknowledgements' anchor='ack'>
  <p>Thanks to Dave Cridland, Kevin Smith, and Matthew Wild for their feedback and suggestions.</p>
</section1>

</xep>