filename= headers in mail

There's an accepted Usenet standard for giving names to files, which looks
like
        Archive-name: foo
or
        Archive-name: bar/Part01
It would be good to bless this as one of the headers.  The tag is a suggested
name, and it's up to the user agent to make sense of it; quite a few user
agents (news readers and source archivers) are coping with it well right now.

See comp.sources.misc or news.answers for real live examples.

--Ed