Comment by Izkata

> Honestly, I really do find the traditional nomenclature to be a little pointless. It seems like the classic saying assumes that it's somehow okay to assume infinite time for re-delivery, but not infinite memory for memoization for some reason.

This is exactly where the argument is coming from. The same people who will say "you can get at most once or at least once, but not only once" don't realize they're doing the exact same thing as the "you can get only once" people, when they criticize the conflation of delivery and processing. They'll argue "delivery" and "processing" have to be kept separate because of memory/storage/bandwidth/etc it uses up in the retries, which is why "only once delivery" can't exist and they actually mean "only once processing", but if you keep that reasoning in mind, there's also no such thing as "at least once delivery" - you'll run out of something at some point (or even just hit your retry limit) and have to drop the retries, resulting in no delivery.

The people saying you can get "only once delivery" by using "at least once"+idempotency are working under other group's definitions, then getting annoyed when the definitions are changed so this implementation of "only once" isn't allowed.