It appears that Keith Moore <moore@xxxxxxxxxxxxxxxxxxxx> said: >On 11/29/22 16:53, John R. Levine wrote: > >> >> I note in passing that if this is a real problem, which I do not >> believe it is, an MDA or MUA can easily look at the date on a message >> and if it's before 2022, the Expires header is not one of ours. > >Oh please. We all know that the date of the message does not imply the >date of the version of the specification that it conforms to. It's a heuristic, in this case, likely to be a pretty good one. But it occurs to me that this same argument could be used to say we can't ever add any new headers, ever. If I define a new "Flurgle:" header, how can we know that someone somewhere didn't already use it to mean something else? It doesn't seem very compelling to me, either for Expires: or for Flurgle:. >dangerous feature, especially in the absence of reliable and verifiable >authentication. That, and the sender should not get to dictate when a >message is deleted by the recipient. Please take a look at section 5, where it says not to do that, and propose text to make it clearer. Also FWIW we've had the Expires: header in usenet since forever, it's always been purely advisory, never been authenticated, and it has turned out to be useful. R's, John -- last-call mailing list last-call@xxxxxxxx https://www.ietf.org/mailman/listinfo/last-call
