On 2/11/2015 7:37 PM, Stephen J. Turnbull wrote:
Only because it already has, except for the RFC, and
mentions the definition of "X-No-Archive: Yes".
In practice, I believe most of the standard (Mailman's Pipermail, mail-archive.com, GMane) and large-scale proprietary archiving engines (Google and Yahoo! Groups) already do.
I wondered if this had been done already somehow, or considered and shot down, and how others handle the problem.
I'm not sure why Palme's I-D wasn't taken to RFC (Informational) status; probably it just was considered insufficiently authoritative since new headers are being invented all the time, eg, X-Spam and relatives aren't in it).
There is an IANA registry for message header fields (see RFC 3864 for registration procedures). Of course, I don't know how many people who write email libraries on any position in the spectrum are aware of this in the first place, so adding X-No-Archive to that list is not likely to matter one whit.