Is "It is supposed to do smth in case of..." correct?

Writing documentation I want to describe an action which a user is expected to do in case of some situation. Is it correct to say it the next way: "It is supposed to do … in case of …", where "it" doesn’t point a subject directly, but only means the generic expectation from any who will read the documentation?

Additionally if it is correct, would negation form "it is supposed NOT to do …" be correct?

Can "supposed" in these cases be replaced with "expected"?

What about "it may not be acceptable to do …"?