[Showing MIME ignorance] Are all of the Content- headers defined as part
of MIME?
The Content- headers that have meaning to bodyparts are defined in RFC1341.
However, there's nothing to prevent the definition of new Content- headers
in future RFCs, and MIME actually goes to some lengths to accomodate
future usage of this sort.
Use of non-bodypart-related non-MIME Content- headers in association with
messages (as opposed to bodyparts) is also perfectly legal.
BTW: I should have mentioned that I'm working on a metamail-based
MIME-PEM processor, which explains my need/desire to know such details.
Sounds great!
Ned