[jerf]

Fundamentals vs. changing tech. "Idempotency" as a concept is fundamental. Which header means what for some cache layer is not. REST unavoidably has a lot of things in it that are changing tech. (Nominally, it has a lot of fundamentals in it too, but per the other REST discussion on the homepage, which fundamentals it encompasses seems to vary on a person-by-person basis.)

[krainboltgreene]

Most of the REST understanding is basically "how do distributed caches work?".

[heavenlyhash]

Thanks, said it better than I could.