XEP-xxxx: Body Markup Hints

This document specifies hints about the markup language used in <body/> elements.
Florian Schmaus
© 1999 – 2020 XMPP Standards Foundation. SEE LEGAL NOTICES.


WARNING: This document has not yet been accepted for consideration or approved in any official manner by the XMPP Standards Foundation, and this document is not yet an XMPP Extension Protocol (XEP). If this document is accepted as a XEP by the XMPP Council, it will be published at <http://xmpp.org/extensions/> and announced on the <standards@xmpp.org> mailing list.
Standards Track
0.0.1 (2017-10-14)
Document Lifecycle
  1. Experimental
  2. Proposed
  3. Draft
  4. Final

1. Introduction

This document specifies hints about the markup language used in <body/> elements found in <message/> stanzas. It also specifies a mechanism to discover support of various markup dialects

2. Markup Languages

This list is not comprehensive and not meant to be. Every markup language in the following list is reasonably readable when treated as plain text.

Table 1: Defined Markup Languages
Markup Language Identifier Name Specification Link
urn:xmpp:bmh:commonmark:0 CommonMark http://spec.commonmark.org/
urn:xmpp:bmh:rst:0 reStructuredText http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html

TODO: Shall we define your own subset of e.g. CommonMark, XMPPMark? :)

3. Exchanging messages with markup formatted bodies

If the textual content of a <message/> contains text which is enriched using a markup language, then the sending client MAY adds a <body-markup-hint/> element qualified by the 'https://xmpp.org/extensions/bmh/0/' namespace with the 'language' attribute set to the Language Identifier of the used markup language.

Note that textual content here means either the content found in <body/> elements or the encrypted textual content, which was encrypted using one of the methods described in Explicit Message Encryption (XEP-0380) [1]

Example 1. A message stanza with a body markup hint
<message from='holden@rocinante.example.org' to='naomi@rocinante.example.org'>
1. Ingredients

    - spaghetti
    - marinara sauce
    - salt

2. Cooking

   Bring water to boil, add a pinch of salt and spaghetti. Cook until pasta is **tender**.

3. Serve

   Drain the pasta on a plate. Add heated sauce.

   > No man is lonely eating spaghetti; it requires so much attention.

*Bon appetit!*
  <body-markup-hint xmlns='https://xmpp.org/extensions/bmh/0/'

4. Discovering Support

It is RECOMMENDED that entities announce the supported body markup languages in its service discovery information as specified in Service Discovery (XEP-0030) [2]. Every markup language is announced as a <feature/> element with the 'var' attribute set to the language identifier of the supported language.

Example 2. A service discovery information with the supported body markup languages
<iq from='julie@eros.example.org'
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <feature var='urn:xmpp:bmh:commonmark:0'/>

5. Business Rules

There MUST be only one <body-markup-hint/> per <message/> stanza, and it applies to all <body/> elements within the same stanza.

6. Security Considerations

TODO: Discuss.

7. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [3].

8. XMPP Registrar Considerations

The XMPP Registrar [4] includes 'https://xmpp.org/extensions/bmh/0/' in its registry of protocol namespaces (see <https://xmpp.org/registrar/namespaces.html>).

TODO: Is it sensible to establish a registry for Markup Language Identifiers?

9. XML Schema

TODO: Add after the XEP leaves the 'experimental' state.

10. Acknowledgements

Thanks to everyone who provided feedback.


Appendix A: Document Information

XMPP Standards Foundation
Standards Track
Last Updated
Approving Body
XMPP Council
Superseded By
Short Name

This document in other formats: XML  PDF

Appendix B: Author Information

Florian Schmaus


This XMPP Extension Protocol is copyright © 1999 – 2020 by the XMPP Standards Foundation (XSF).


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## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##

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IPR Conformance

This XMPP Extension Protocol has been contributed in full conformance with the XSF's Intellectual Property Rights Policy (a copy of which can be found at <https://xmpp.org/about/xsf/ipr-policy> or obtained by writing to XMPP Standards Foundation, P.O. Box 787, Parker, CO 80134 USA).

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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 <standards@xmpp.org> discussion list.

Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.

Errata can be sent to <editor@xmpp.org>.

Appendix F: Requirements Conformance

The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".

Appendix G: Notes

1. XEP-0380: Explicit Message Encryption <https://xmpp.org/extensions/xep-0380.html>.

2. XEP-0030: Service Discovery <https://xmpp.org/extensions/xep-0030.html>.

3. 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/>.

4. 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 <https://xmpp.org/registrar/>.

Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

  1. Version 0.0.1 (2017-10-14)

    First draft.