I mildly prefer header-set to multipart/foo. I prefer either to
multipart/references without the start parameter, and definitely unprefer
the start parameter.
Yeah, at this point I don't see any reason to keep the start parameter.
Just make the first component be the "start" component. That makes it
equivalent to multipart/header-set, except that with /references the
objects can reference one another.
A clever mail reader could then decide, after reading the first component
only, whether it should (a) handle the entire multipart internally, (b) run a
display program and pipe the object to its standard input (if there's only one
object being referenced), or (c) put the component objects into temp files (if
the objects reference one another).
The real question is: is there a need for MIME objects that can reference one
another? I think there is. An application/html document is a single "page",
yet you usually peruse them in sets, and mailing a set of such documents
around seems like a natural thing to do. (Mac users mail around hypercard,
stacks, don't they?)
At the same time, I don't want mime mail readers to incur the overhead of
copying components of a multipart/references set to separate files, if it's
not needed for that application.
Keith