In particular, I think we are missing a key distinction that the MIME
content-type is not so much the "type" of a resource, but the
type of a particular *publication* of a resource.
This is a very good distinction, and a very succint summary. Well
done.
Relative to the issue of bundling resources with a document,
I recently put up a proposal for Document Resource Links, for XML. See
http://www.ascc.net/~ricko/drlove.htm
Rather than extending the MIME headers with lots of
parameter, perhaps just the URI of a single resource like that would allow
greater
extensibility.
Yes, I think this is absolutely the right way to go. The only thing I would
add is that packaging itself has many facets: the "catalog" (drlove, XPDL,
etc.)
definition, packaging in MIME multipart/*, resource name aliasing, push vs.
pull,
mixed mode push/pull, etc. that all need to be considered.
When we considered this before (for MIME SGML), we concluded that MIME
*already*
provides sufficient infrastructure... you only really needed to register a
few
more MIME types for the primary objects (document instances, DTD's, SGML
declarations< etc.) and that the rest of the requirements really fall onto
the "catalog", or perhaps as you might call it, the "publication
specification".
And the URI acts as a "publication type name".
This is a nice feature.