It's not clear that specialized media types solve any problem at all,
in the case of XML that already contains a document declaration.
Ned corrected me. There are *some* problems that might be solved by
specialized media types.
The overhead of having to open up every XML document to find out what
document type it is is not practical. As in the case of email, all I should
have to do is ask for a particular type of object from the store and get it.
In addition, though, we also want to get at subtypes of objects. Or in the
case of MIME type/subtypes, this would be the "sub-sub type". For example,
for a calendar object (text/calendar) we want to pull to the client just the
"event invitations". This would be the "sub sub type" of type=text,
subtype=calendar.
This is a good example of a problem that specialized media types won't solve.
You might also want to scan your email for "event invitations from my boss",
and you can't solve that problem with specialized MIME media types. So the
question is: are there any realistic cases where having a "text/calendar"
distinction in the email header actually helps substantially in deciding
which email bodies to retrieve?
Larry