How does one reliably track down all of the defined RFC [2]822
headers? That is, when proposing a new header, how is one to be sure that
it is not already defined somewhere?
Simple: Search all the RFCs and internet-drafts. This is hardly rocket science.
But as a practical matter the real issue isn't standardized use, or even
proposed use in a standard. It is the fact that anyone can use any field name
at any time without any specification whatsoever. This is much more difficult
to gauge. Personally, I do it by keeping track of all the fields I encounter
that seem reasonable -- 511 so far.
I would like to suggest taking Jacob's draft, and:
(a) adding an IANA considerations section to create a message header
registry (or creating a new companion document)
(b) incorporating all of the standards-track-defined headers noted in
Jacob's draft into the registry
(c) issuing the result as BCP RFC(s)
(d) noting in the RFC index that the document updates RFC 2822.
Before taking on any drafting work, I'd like to gauge the sense of whether
this general approach is likely to fly.
Seems to me like a lot of work that won't really address the problem.
Ned