Jim, I've been quiet because I've been away from my mail for a few
weeks, but here's the latest:
Someone suggested to me a *good* reason for not allowing multiple types
in the "type" field of the the Content-type header, and Henry Spencer
alluded to it on this list:
Just as the "Keyword" header is rarely filled out usefully in netnews,
the multiple types would rarely be specified correctly. To do so would
require an format-knowledgable application which would be able to scan
the document, and produce a list of media types in it. It would be
unlikely that such an application would exist, for most mixed-media
document formats. (I agree with this assessment (and think it applies
to "multipart", as well).) Therefore, the mixed list of types would be
unreliable, and therefore useless.
So let's proceed with just a single "type" entry in the header,
recognizing that we are going to be dealing with lots and lots of
headers of the form
Content-type: APPLICATION/MS-WORD;3
I think as well, that we have to be very careful with allowing things to
be registered under IMAGE, or TEXT-PLUS. Are multi-page images
(PostScript) valid under IMAGE, or should they come under APPLICATION?
If under IMAGE, what do we then say about multi-page images with a
defined temporal spacing between images (animations)? How about troff
that contains eqn? Fair game under TEXT-PLUS, or does it have to go
under APPLICATION?
Bill