Currently, we define the X-Message-ID-Hash as the base32 encoding of the sha1 hash of the Message-ID content (sans angle brackets as defined in RFC 5322). The suggestion is made that List-Post value should be added to this hash so as to be able to distinguish cross-posted messages.
This should be fine, and pretty easy. My only concern is that the header name is now a misnomer.
I wonder, is it worth coming up with a better header? Now's the time to do it since it's likely that there are almost no consumers of this standard.
What about `Permalink-Hash` ?