Oops, putting it in parentheses was just stupid. I didn't mean to
propose to put it in comments; obviously a different syntax is needed.
The only advantage I see to putting the encoding into the content-type
field is that it makes it more clear that they're related, i.e. that it
is reasonable to say things like "multipart content-types should use NO
encodings." Clearly a disadvantage is that an MTA that needs to muck
with encoding will then also need to rewrite a content-type header. If
people think that its reasonable to say that the content of the
content-type field can determine what, if anything, is permitted in the
content-encoding field, then I'm happy to keep the two fields separate.
-- Nathaniel