CURRENT MEETING REPORT Minutes from the BOF on sending HTML-formatted messages in e-mail at the IETF meeting in Dallas, December 1995 Reported by Jacob Palme 1. Several implementations are already ready or well under way which provide e-mail with the functionality of sending HTML-formatted messages. An IETF standard on how to send such messages is urgently needed. Representatives of three such ongoing implementations identified themselves at the BOF meeting (Mark Joseph at Wollongong, Alex Hopmann at Resnova and Jacob Palme at Stockholm University/KTH). One more ongoing implementation is known but was not represented at the meeting (Martin R Raskovsky at Atelier). 2. Even though the BOF was held during the lunch hour (the only empty slot available for us) 18 people participated in the BOF meeting. 3. The BOF decided to ask IESG to start an IETF working group on the topic of "Sending HTML in e-mail". A tentative acronym for the new group is MHTML or MAILHTML. 4. We discussed the scope for the new working group and agreed on the following: 4a. The main task of the new working group is defining how to send HTML messages in e-mail in a way which allows interoperability between WWW and e-mail systems. 4b. The result might produce both a standard and an informa- tional RFC, since some issues (like URLs referring to embedded objects) might require standards, while other issues might be handled by informational RFCs. The group will also consider using existing or forth- coming standards, like Multipart/related and Content- Disposition. The group might want to modify Content- Disposition. The group might want to ask IESG to shift Multipart/related and Content-Disposition from experi- mental to standards track, if this is needed for the task of this group. Palme [Page 1] Minutes from Dallas BOF on HTML in e-mail December 1995 4c. The group should develop standards which are suitable for both combined web browsers and e-mail software and separate e-mail software which uses web browsers as helper applications to display HTML-formatted e-mail body parts. 4d. The working group should develop a standard which works for both connected and disconnected e-mail user agents. 4e. The goal for the working group should be to allow full HTML documents to be sent as e-mail without changes to them. If however, the HTML documents contain hyperlinks to other body parts in the same message, the group may identify requirements on the format of such hyperlinks. 4f. The group might identify new MIME headers or MIME header parameters. However, changes to the HTML or SMTP speci- fications are however not within the scope of the group. 4g. The group shall not develop standards for the following tasks, but will consider these tasks in order to develop a standard which is a suitable basis for them: - Web browsing via e-mail (i.e. mail servers which give access to WWW databases). - Forms and other embedded executable content. - Sending PDF (=Adobe Acrobat) format documents via e-mail. 5. The following tentative schedule was agreed upon: March 1996: Clarify issues and a first draft text for the standards. June 1996: Rough consensus on the major contents of the standard. Fall 1996: At least two independent and interworking implementations. (Four such implementations underway are already known to exist.) December 1996: Finish and submit standards track proposal. It would be an advantage if the group work would go even faster than this. 6. We propose Ed Levinson as a chairman and Jacob Palme as an editor. 7. Pete Resnick promised to develop charter for the new group. Palme [Page 2] Minutes from Dallas BOF on HTML in e-mail December 1995 8. Jacob Palme has started a mailing list for the group. The name of the mailing list is mhtml@segate.sunet.se. To subscribe to the list, send a message to listserv@segate.sunet.se which contains the text sub mhtml Archives are available by anonymous ftp from ftp://segate.sunet.se/DISK2:[AFTP.LISTS.MHTML]mhtml.log9512 or with shorter message headers from ftp://segate.sunet.se/DISK2:[AFTP.LISTS.MHTML]mhtml.digest The archives are also available by e-mail. Send a message with the text get mhtml log9512 or get mhtml digest to listserv@segate.sunet.se 9. We did not have much time to discuss the technical issues, but below is reported some problems identified: 9a. One problem is the requirements of two developer communities, one which develop combined web browsers and e- mail systems, and one which develop e-mail systems which are capable of showing HTML messages by using web browsers as helper applications. These communities may have different requirements, and solutions must be found which satisfy both communities. 9b. Another problem is that we want to develop proposed IETF standards, but we might also wish to use functionality which is or which will be experimental IETF standards (examples: (a) the Multipart/related content type (b) the Content-Disposition mime header). On the one hand, it seems silly not to use already defined functionality, on the other hand, IETF might not allow proposed standards to reference experimental standards. We need advice from the area directors on this. 10. Using Multipart/related was preferred if IETF rules allow it. In particular, we noted that the MIME specification states that multipart/unknown is to be treated as multipart/mixed, which means that multipart/related will work also with receiving mail systems which do not understand multipart/related. 11. If HTML documents with relative URLs are sent as e-mail, then the base for these relative URLs might be indicated in three ways: (a) Using a BASE element within the HTML document. Palme [Page 3] Minutes from Dallas BOF on HTML in e-mail December 1995 (b) Using a MIME header indicating the originating URI of the HTML document itself, such a header might be named Content- Location. (c) Using a MIME header indicating the base for relative URI-s within the MIME message, such a header might be named Base or Content-Base and is already specified in RFC 1808. 12. We discussed the syntax for embedding URLs in MIME messages. We noted that several different IETF work items have encountered this problem, and that the same syntax should be used in all cases where URL-s are needed in MIME messages. The most fully developed solution is specified in "draft-ietf-mailext-acc-url-01.txt", so we agreed to use this syntax. In particular, this syntax indicates that double- quotes (") are to be used to delimit the URL. 13. A large number of other issues were identified, based on the discussions in the ietf-types@uninett.no mailing list, but which we did not have time to discuss during the meeting. Palme [Page 4]