On Thu, May 22, 2025 at 08:12:13AM -0400, Rich Kulawiec wrote:
I think a better approach is to figure out what needs to be changed/ fixed/added to RFC 4155 so that it covers the variants that arisen, and to create a superseding RFC that updates it. This won't fix all the problems that have arisen as a result of choices (or mistakes) made along the way, but it should at least document those problems so that folks have a fighting chance of dealing with them. I think it'd be good to have a single definitive-as-possible reference stored somewhere that's like to be around for a while, and well, an IETF standard is about as "permanent" as we're likely to get.
So you just want documentation of what exists? That's fine. (RFC 4155 format does not seem to exist. Far as I know, it was never implemented, and no such mbox files were ever written.)
An RFC is not the right place for that documentation, though. The IETF defines only network protocols. It declares that whatever happens locally, within computers, off the network, is beyond the IETF's scope. That local action includes file formats, of course.
RFC 4155 was a trick, an attempt to sneak in a file format definition. It claims to define only a new MIME type, not a file format, but I don't believe that was the whole intent. For that reason, I think that RFC should not have been written. (Also because the MIME type it defines doesn't work, and wouldn't be of much use if it did.)
Documentation of mbox should be somewhere else, not an RFC. How about Wikipedia? It already has an article about mbox.
