XEP-0091: Legacy Delayed Delivery

Abstract: This specification provides historical documentation of the legacy jabber:x:delay namespace, which has been deprecated in favor the urn:xmpp:delay namespace defined in XEP-0203.
Author: Peter Saint-Andre
Copyright: © 2003 – 2009 XMPP Standards Foundation. SEE LEGAL NOTICES.
Status: Obsolete
WARNING: This document has been obsoleted by the XMPP Standards Foundation. Implementation of the protocol described herein is not recommended. Developers desiring similar functionality are advised to implement the protocol that supersedes this one (XEP-0203).
Superseded By: XEP-0203
Type: Historical
Version: 1.4 (2009-05-27)

Document Lifecycle

Experimental
Proposed
Active
Deprecated
Obsolete

1. Introduction¶

Note: This specification has been deprecated in favor of Delayed Delivery (XEP-0203) [1].

This document provides canonical documentation of the 'jabber:x:delay' namespace, which was long used by Jabber applications to mark message or presence stanzas as delivered with a delay. This document is of historical importance only, since it has been deprecated in favor of Delayed Delivery (XEP-0203) [1].

2. Protocol Definition¶

The 'jabber:x:delay' namespace is used to provide timestamp information about data stored for later delivery. The most common uses of this namespace are to stamp:

A message that is sent to an offline entity and stored for later delivery.
The last presence update sent by a connected node to a host.
Messages cached by a multi-user chat room for delivery to new participants when they join the room.

Information about the delivery delay is communicated by adding to the <message/> or <presence/> stanza one and only one <x/> child qualified by the 'jabber:x:delay' namespace. This information is added by the server or component that delivers the information. The following attributes are allowed on the <x/> element:

from -- The Jabber ID of the entity that originally sent the XML stanza or that delayed the delivery of the stanza (for example, the address of a multi-user chat room). This attribute is RECOMMENDED.
stamp -- The time when the XML stanza was originally sent. The format SHOULD be "CCYYMMDDThh:mm:ss" (see A Note on Time Formats below). This attribute is REQUIRED.

In addition, the <x/> element MAY contain XML character data that provides a natural-language description of the reason for the delay.

3. Examples¶

Example 1. Receiving a Message Sent While Offline¶

<message
    from='[email protected]/orchard'
    to='[email protected]'
    type='chat'>
  <body>
    O blessed, blessed night! I am afeard.
    Being in night, all this is but a dream,
    Too flattering-sweet to be substantial.
  </body>
  <x xmlns='jabber:x:delay'
     from='capulet.com'
     stamp='20020910T23:08:25'>
    Offline Storage
  </x>
</message>

Example 2. Receiving the Last Presence Update of Another Entity¶

<presence from='[email protected]/balcony' to='[email protected]'>
  <status>anon!</status>
  <show>xa</show>
  <priority>1</priority>
  <x xmlns='jabber:x:delay'
     from='[email protected]/balcony'
     stamp='20020910T23:41:07'/>
</presence>

Example 3. Receiving Cached Messages from a Conference Room¶

<message
    from='[email protected]/secondwitch'
    to='[email protected]/laptop'
    type='groupchat'>
  <body>
    By the pricking of my thumbs,
    Something wicked this way comes.
    Open, locks,
    Whoever knocks!
  </body>
  <x xmlns='jabber:x:delay'
     from='[email protected]'
     stamp='20020910T23:05:37'/>
</message>

4. A Note on Time Formats¶

XML Schema Part 2 [3]. Because a large base of deployed software uses the old format, this document specifies that applications using 'jabber:x:delay' SHOULD use the old format, not the format defined in XEP-0082. The timezone is be understood as UTC.

5. Security Considerations¶

Data qualified by the 'jabber:x:delay' 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.

6. IANA Considerations¶

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [4].

7. XMPP Registrar Considerations¶

The 'jabber:x:delay' namespace is included in the protocol namespaces registry maintained by the XMPP Registrar [5].

8. XML Schema¶

<?xml version='1.0' encoding='UTF-8'?>

<xs:schema
    xmlns:xs='http://www.w3.org/2001/XMLSchema'
    targetNamespace='jabber:x:delay'
    xmlns='jabber:x:delay'
    elementFormDefault='qualified'>

  <xs:annotation>
    <xs:documentation>
      The protocol documented by this schema is defined in
      XEP-0091: http://www.xmpp.org/extensions/xep-0091.html

      NOTE: This protocol has been deprecated in favor of the
            Delayed Delivery protocol specified in XEP-0203:
            http://www.xmpp.org/extensions/xep-0203.html
    </xs:documentation>
  </xs:annotation>

  <xs:element name='x'>
    <xs:complexType>
      <xs:simpleContent>
        <xs:extension base='xs:string'>
          <xs:attribute name='from' type='xs:string' use='optional'/>
          <xs:attribute name='stamp' type='xs:string' use='required'/>
        </xs:extension>
      </xs:simpleContent>
    </xs:complexType>
  </xs:element>

</xs:schema>

Appendices

Appendix A: Document Information¶

Series: XMPP Council
Dependencies: XMPP Core
Supersedes: None
Superseded By: XEP-0203
Short Name: x-delay
Schema: <HTML

This document in other formats: XML CC-BY-SA 2.0 license.

Appendix D: Relation to XMPP¶

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 6120) and XMPP IM (RFC 6121) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.

Appendix E: Discussion Venue¶

The primary venue for discussion of XMPP Extension Protocols is the <https://xmpp.org/extensions/xep-0203.html>.

2. XEP-0082: XMPP Date and Time Profiles <https://xmpp.org/extensions/attic/

Version 1.1 (2004-02-24)¶
Corrected several small textual errors.
psa
Version 0.1 (2003-05-22)¶
Initial version.
psa

Appendix I: Bib(La)TeX Entry

@report{saint-andre2003x-delay,
  title = {Legacy Delayed Delivery},
  author = {Saint-Andre, Peter},
  type = {XEP},
  number = {0091},
  version = {1.4},
  institution = {XMPP Standards Foundation},
  url = {https://xmpp.org/extensions/xep-0091.html},
  date = {2003-05-22/2009-05-27},
}

END