Network Working Group R. Cadenhead
Internet-Draft G. Smith
Expires: November 22, 2006 RSS Advisory Board
J. Hanna
B. Kearney
RSS-DEV Working Group
May 22, 2006

The application/rss+xml Media Type
draft-rss-media-type-00

Status of this Memo

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Abstract

This document specifies the Media Type for RSS, a data description
and syndication format.

1. Introduction

RSS is an XML-based document format for the syndication of web
content so that it can be republished on other sites or downloaded
periodically and presented to users.

RSS is currently used for a number of applications, including news
headline syndication, weblog content distribution, and the exchange
of other timely information such as software release notes.

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There are a number of revisions [1][2][3][4][5][6] of RSS in active
use today, all of which derive from the original format RDF Site
Summary (RSS) 0.9 [7].

Because of the common origin and the wide implementation of these
revisions, general-purpose RSS clients typically support all of the
revisions to maximize interoperability.

This memo defines a media type, "application/rss+xml", for all
versions of RSS.

2. Registration Information

To: ietf-types@iana.org

Subject: Registration of MIME media type application/rss+xml

MIME media type name: application

MIME subtype name: rss+xml

Required parameters: none

Optional parameters:

charset

This parameter has semantics identical to the charset parameter of
application/xml as specified in [RFC3023].

version

This parameter indicates the version of RSS employed in the
document. This value should be the URI of an XML Namespace [8]
for a revision that defines a namespace (e.g.,
"http://purl.org/rss/1.0/" for RDF Site Summary (RSS) 1.0) or a
number for a version that does not (e.g., "2.0" for RSS 2.0).

Encoding considerations:

They are the same as the encoding considerations of
application/xml as specified in [RFC3023], Section 3.

Security considerations:

They include all of the security considerations of
application/xml as specified in [RFC3023], Section 10.

Additionally, some RSS elements allow the delivery of HTML and
XHTML, markup languages that include many elements that are
considered unsafe because they expose clients to one or more
types of attack. See the security sections of [RFC2854] and
[HTML401] for guidance.

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Clients built on software libraries or applications that process
RSS must ensure that the code does not bring the file into a local
context, where it is treated as a trusted source.

RSS clients should pay particular attention to the security of the
contents of the HTML and XHTML elements META, SCRIPT and STYLE;
the HTML and XHTML attributes ACTION, BACKGROUND, CITE, CLASSID,
CODEBASE, DATA, HREF, LONGDESC, PROFILE, and USEMAP; and all
proprietary elements and attributes, particularly the BGSOUND,
EMBED and LAYER elements. Other elements also may have security
implications.

RSS documents may indirectly link to executable content. Embedded
content in other formats delivered over RSS, such as HTML and
XHTML, also may in turn directly contain or indirectly reference
executable content.

Namespace extensions allow RSS documents to directly contain
arbitrary content, which could be executable content or content
types that may in turn directly or indirectly contain such
content. Presentation of such content is always optional for RSS
clients and must only be done when the content type is known and
the security implications of that type have been considered.

Published specification(s):

RDF Site Summary (RSS) 0.9 [7]

RSS 0.91 Spec, revision 3 [1]

RSS 0.91 [2]

RSS 0.92 [3]

RDF Site Summary (RSS) 1.0 [4]

RSS 2.0 [5]

RSS 2.0.1, revision 6 [6]

Applications which use this media type:

RSS is supported by client software called readers, newsreaders,
or aggregators and a large number of content management systems
that publish and consume the format. It also is supported by many
applications that produce and consume HTML and XHTML.

2.1 Additional information:

Magic number(s):

There is no single initial byte sequence that always is present in
RSS documents. See [RFC3023] for information about the

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identification of XML media types.

File extension(s):

.rss (all versions), .xml (all versions), and .rdf (for RDF Site
Summary (RSS) 0.9 and 1.0)

Macintosh File Type Code(s): TEXT

Person & email address to contact for further information:

The authors of this memo

Intended usage: COMMON

Further information:

The choice of "application/rss+xml" as the desired media type for
RSS was recommended by the RSS-DEV Working Group [9] and RSS
Advisory Board [10], organizations that publish and support the
two most widely implemented versions of RSS.

Author/Change controller(s):

RDF Site Summary (RSS) 0.9 was a product of Netscape
Communications authored by Dan Libby

RSS 0.91 Spec, revision 3 was a product of Netscape Communications
authored by Libby

RSS 0.91 was a product of UserLand Software authored by Dave
Winer

RSS 0.92 was a product of UserLand Software authored by Winer

RSS 1.0 was a product of the RSS-DEV Working Group [9] and was
authored by Gabe Beged-Dov, Dan Brickley, Rael Dornfest, Ian
Davis, Leigh Dodds, Jonathan Eisenzopf, R.V. Guha, Ken MacLeod,
Eric Miller, Aaron Swartz, and Eric van der Vlist

RSS 2.0 was a product of UserLand Software authored by Winer

RSS 2.0.1, revision 6 was a product of the Berkman Center for
Internet & Society at Harvard Law School and the RSS Advisory
Board [10] and was authored by Winer

References

[HTML401] Raggett, D., Le Hors, A., and Jacobs, I., "HTML 4.01
Specification", December 1999, W3C Recommendation,

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[RFC2854] Connolly, D., and Masinter, L., "The 'text/html' Media
Type", RFC 2854, June 2000.

[RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media
Types", RFC 3023, January 2001.

[1] Libby, D., "RSS 0.91 Spec, revision 3", July 1999,
.

[2] Winer, D., "RSS 0.91", July 1999,

[3] Winer, D., "RSS 0.92", December 2000,

[4] Beged-Dov, G., Brickley, D., Dornfest, R., Davis, I.,
Dodds, L., Eisenzopf, J., Guha, R., MacLeod, K., Miller,
E., Swartz, A., and E. van der Vlist, "RDF Site Summary
(RSS) 1.0", May 2001,

[5] Winer, D., "RSS 2.0", August 2002,

[6] Winer, D., "RSS 2.0.1, revision 6", January 2005,

[7] Libby, D., "RDF Site Summary (RSS) 0.9", July 1999,

. [8] Bray, T., Hollander, D., and Layman, A, "Namespaces in XML", January 1999, W3C Recommendation,
. [9]
. [10]
. Authors' Addresses Rogers Cadenhead, RSS Advisory Board Email: workbench@cadenhead.org URI: http://www.cadenhead.org/workbench/ Jon Hanna, RSS-DEV Working Group Email: jon@hackcraft.net URI: http://www.hackcraft.net/ Bill Kearney, RSS-DEV Working Group Email: wkearney@syndic8.com URI: http://www.ideaspace.net/users/wkearney/ Cadenhead-Hanna, et al. Expires November 22, 2006 [Page 5] Internet-Draft The application/rss+xml Media Type May 22, 2006 Greg Smith, RSS Advisory Board Email: ecomputerd@yahoo.com URI: http://www.feederreader.com/ Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Cadenhead-Hanna, et al. Expires November 22, 2006 [Page 6]