Such as in which situations? It's not obvious at all, so a reader (that is, an API designer) is on their own to try and divine whether there's any real reason to follow this "standard" instead of doing things in the more natural and standard way.
This is my point. Not that it's hard to read these RFCs... but that they're often so vague, and is so often hard to know whether there's any benefit at all to following them in one's specific situation.
That doesn't stop self-appointed standards cops from smacking people down.