Craig Loomis writes:
Globally unique IDs, hashed IDs, etc., are very appealing from
various CS-y and techie points of view, but are simply not memorable
to humans or knowable by dumb external programs. I think as much, or
more, effort should be put into delivering a straightforwardly useable
naming scheme as goes into making an arbitrary message recoverable
from anywhere. Basically, "friendly URLs" should be a primary
requirement, not an optional afterthought for careless geeks like me
to get wrong later....
Friendly URLs *are* a primary requirement. The point is that to make them *reliable* as well, either a globally unique ID is needed, or individual site admins must suffer through hard-to-document constraints on what they can do with their archives. Note that the system you describe based on the post_id member demonstrates the value of a unique ID.
"Sufficient reliability" is not a tough requirement for an individual admin to achieve, as you have demonstrated. It's much more exacting for the Mailman developers, who need to satisfy both sites with different needs *and* archivers with different features.
As an aside on other discussions, can you get away without using
Message-ID or Date?
No. Not all recipients of the messages get them through the list. Once again, Mailman developers have to consider that situation, while in your situation you may not need to worry about it.