<p>Although the XMPP protocol extension defined in &xep0091; provides a way to communicate that an XML stanza (typically a &MESSAGE; or &PRESENCE; stanza) has been delivered with a delay, the timestamp format defined in that document does not adhere to the recommended date and time profiles for XMPP protocols defined in &xep0082;. Therefore, this document defines a replacement for <cite>XEP-0091</cite> which enables communication of delayed delivery information while adhering to <cite>XEP-0082</cite>.</p>
<p>The XML namespace defined herein is used to provide timestamp information about data stored for later delivery. The most common uses of this namespace are to stamp:</p>
<ul>
<li>A message that is sent to an offline entity and stored for later delivery (see &xep0160;).</li>
<li>The last available presence stanza sent by a connected client to a server.</li>
<li>Messages cached by a &xep0045; room for delivery to new participants when they join the room.</li>
</ul>
<p>Information about the delivery delay is communicated by adding to the <message/> or <presence/> stanza one and only one <delay/> child qualified by a namespace to be issued when this specification advances to a status of Draft. This information is added by the server or component that delivers the stanza. The following attributes are defined for the <delay/> element:</p>
<tablecaption='Defined Attributes'>
<tr>
<th>Element</th>
<th>Definition</th>
<th>Inclusion</th>
</tr>
<tr>
<td><from/></td>
<td>The Jabber ID of the entity that originally sent the XML stanza or that delayed the delivery of the stanza (e.g., the address of a multi-user chat room).</td>
<td>RECOMMENDED</td>
</tr>
<tr>
<td><stamp/></td>
<td>The time when the XML stanza was originally sent. The format MUST adhere to the dateTime format specified in <cite>XEP-0082</cite> and MUST be expressed in UTC.</td>
<td>REQUIRED</td>
</tr>
</table>
<p>In addition, the <delay/> element MAY contain XML character data that provides a natural-language description of the reason for the delay.</p>
</section1>
<section1topic='Examples'anchor='examples'>
<examplecaption='Receiving a Message Sent While Offline'><![CDATA[
<p>This protocol was designed in a way that makes migration from <cite>XEP-0091</cite> straightforward. All attributes present in the 'jabber:x:delay' namespace are present in the namespace defined herein. However, this document specifies a different format for the value of the <stamp> attribute (compliant with <cite>XEP-0082</cite>).</p>
<p>Implementations that support <cite>XEP-0091</cite> should support the protocol defined herein as soon as possible, but should continue to support the protocol defined in <cite>XEP-0091</cite> for backwards compatibility until the status of that specification is changed to Obsolete.</p>
<p>Delayed delivery data can expose information about the sender's presence on the network at some time in the past. However, this introduces no new vulnerabilities, since the same information would have been available in real time.</p>
<p>Until this specification advances to a status of Draft, its associated namespace shall be "http://www.xmpp.org/extensions/xep-0203.html#ns"; upon advancement of this specification, the XMPP Registrar shall issue a permanent namespace in accordance with the process defined in Section 4 of &xep0053;.</p>