Arnt Gulbrandsen <arnt(_at_)gulbrandsen(_dot_)priv(_dot_)no> writes:
Is there a single (or a very few) interoperably used fields, in
practice? I've heard of X-No-Archive and Archive - who supports those
two?
Archive is very sparsely used, and I'm not sure if it's really used by
anyone in an interoperable fashion. X-No-Archive is widely respected by a
variety of software, most notably Google Groups.
It should be considered purely a request, IMO, since the definition of
archive is iffy and it's hard to really formalize policy without getting
into very complex rules engines.
Note that X-No-Archive applies to the entire message. The implications of
a Content-Disposition parameter that could be applied to arbitrarily
nested parts of a complex MIME message and not visible in the top-level
headers for an implementor trying to honor it are a bit troubling to me.
Without it being trivial to determine the archivability of a message, I
expect many archives wouldn't bother.
--
Russ Allbery (rra(_at_)stanford(_dot_)edu)
<http://www.eyrie.org/~eagle/>