For example, if this were a fax service, it could Accept: text/*,
application/postscript, image/* (but not, say, audio/*); if it were a
answering-machine application, it might accept only audio/*.
The client would do the appropriate thing for the client application,
e.g., prompt for a file name of the appropriate type, or, if audio was
being accepted, allow for recording of an audio clip...
The question is, what's the `right way' to handle this between HTML
and HTTP? Does this require a separate protocol? Should the `Accept:'
headers be part of the form?
Personally, I like putting them in the form if only so that you could
mail someone a form rather than always deliver it to them via http...