MIME media types
This document lists a few things that are nice to know about MIME
media types, as I understand them.
NOTE: THis document was written in 1996, and is badly outdated!
Official registration procedures
MIME types should be registered with IANA.
The rules for registration are in the internet-draft
"draft-ietf-822ext-mime-reg-04.txt", which was approved as Best
Current Practice on August 23, 1996.
What IANA thinks is registered at any time can be found in the
IANA
FTP archive. The directories here contain the actual application
forms for registration.
The discussion list for MIME types is currently hosted at
ietf-types@alvestrand.no. You can subscribe by writing to
ietf-types-request@alvestrand.no and including the word "subscribe" in
the BODY of the message.
The list should also be reachable as ietf-types@iana.org; this address
should be stable "forever", no matter where the physical list is hosted.
Archives of the list are found at http://eikenes.alvestrand.no/mailman/listinfo/ietf-types.
There is no FAQ (apart from this Web page), and the list is not
gatewayed to any Usenet newsgroup (that I know of).
Issues to be aware of in type registration
When registering a new type, you ought to be aware of the following:
- Subtypes are either old, IESG-approved or private. Private subtypes
start with "vnd." or "prs.", and may be of the form
"vnd.company.type", or simply "vnd.type".
- The IANA will register anything under "vnd." and "prs.", with
or without review on the ietf-types list. However, review is
strongly recommended!
- New toplevel types have to be standards-track RFCs. Only one
toplevel type, the "MODEL" type, has been registered.
(draft-nelson-model-mail-ext-05.txt, approved by the IESG on
September 19, 1996)
- New transfer encodings have to be specified by changing the
MIME spec, not by registration.
- UUEncode is unsuitable for a MIME transfer encoding. See this presentation to learn why.
Because the process used to be a bit difficult, a lot of "x-" types
have been registered.
MIME conversion tables to X.400
Conversions between MIME and X.400 should be done according to RFC 1494.
The IANA registry of such conversions is part of the file
media-types,
according to RFC
1700.
Harald.T.Alvestrand@uninett.no
Last modified: Wed Oct 16 21:42:37 1996