Network Working Group M. Duerst Internet-Draft W3C Expires: January 17, 2005 July 19, 2004 The Archived-At Email Header draft-duerst-archived-at-01 Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on January 17, 2005. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This memo defines a new email header, Archived-At:, to provide a direct link to the archived form of an individual mail message. Duerst Expires January 17, 2005 [Page 1] Internet-Draft The Archived-At Email Header July 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Syntax Definition . . . . . . . . . . . . . . . . . . . . . . 3 3. Supporting Nested Lists . . . . . . . . . . . . . . . . . . . 3 4. Implementation Considerations . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . 6 Duerst Expires January 17, 2005 [Page 2] Internet-Draft The Archived-At Email Header July 2004 1. Introduction [RFC2369] defines a number of header fields that can be added to email messages send by email distribution lists. One of them is the 'List-Archive' header field that describes how to access archives for the list. This allows to access the archives as a whole, but not the individual message. There is often a need or desire to refer to the archived form of a single message. This memo defines a new header, 'Archived-At', to refer to a single message in an archive. 2. Syntax Definition The name of the header field is 'Archived-At'. The content of the header field is an URI [RFC2369] pointing to an archived version of the message. This header field is subject to the encoding and character restrictions for mail headers as described in [RFC2822]. Additionally, the URI content is further restricted to the set of URI safe characters [RFC2396]. This syntax is kept very simple on purpose, it does not allow comments, nor does the URI have to be enclosed with '<' and '>'. In this points, the syntax is different from [RFC2369]. 3. Supporting Nested Lists If a message is forwarded from a list to a sublist, and both lists support adding the Archived-At header field, then the sublist should add a new Archived-At header field without removing the already existing one(s). 4. Implementation Considerations This section shortly discusses some implementation considerations. Mailing list expanders and email archives are often separate pieces of software. This may make it difficult for the mailing list expander to create an 'Archived-At' header field. W3C uses a setup that allows to use the message id of the incoming mail, combined with a lookup in a database and HTTP redirection, to find the actual message. As an example, the URI "http://www.w3.org/mid/1057271304.16158.44.camel@dirk.dm93.org", containing the message id "1057271304.16158.44.camel@dirk.dm93.org", is redirected to the usual mailing-list archive URI at Duerst Expires January 17, 2005 [Page 3] Internet-Draft The Archived-At Email Header July 2004 http://lists.w3.org/Archives/Public/public-ietf-w3c/2003Jul/ 0000.html. When using the message id to create an address for the archived mail, care has to be taken to escape characters in the message id that are not allowed in the URI. Depending on the URI scheme for the URI used, the message can be made available in more than one format. As an example, a HTTP URI can make use of content negotiation to for example serve the message both as text/html for human consumption in a browser and as message/rfc822 [RFC2046] for use by a mail user agent without loss of information. 5. Security Considerations There are many potential security issues when activating and dereferencing an URI. For more details, please see [RFC2396]. 6. IANA considerations Currently, there is no IANA registry for header fields. If and when there is such a registry, the Archived-At header will have to be registered. 7. Acknowledgements The members of the W3C system team, in particular Gerald Oskoboiny, Olivier Thereaux, and Jose Kahan, created the mid-based email archive lookup system and the experimental form of the Archived-At header. Pete Resnik provided the motivation for writing up this draft. 8 References [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996. [RFC2369] Baer, J. and G. Neufeld, "The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields", RFC 2369, July 1998. [RFC2396] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. [RFC2822] Resnick, P., "Internet Message Format", RFC 2822, April 2001. Duerst Expires January 17, 2005 [Page 4] Internet-Draft The Archived-At Email Header July 2004 Author's Address Martin Duerst (Note: Please write "Duerst" with u-umlaut wherever possible, for example as "Durst in XML and HTML.) World Wide Web Consortium 200 Technology Square Cambridge, MA 02139 U.S.A. Phone: +1 617 253 5509 Fax: +1 617 258 5999 EMail: duerst@w3.org URI: http://www.w3.org/People/D%C3%BCrst/ Duerst Expires January 17, 2005 [Page 5] Internet-Draft The Archived-At Email Header July 2004 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 IETF's procedures with respect to rights in IETF Documents can be found in BCP 78 and BCP 79. 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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 (2004). 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. Duerst Expires January 17, 2005 [Page 6]