I occasionally find myself in a situation where an undermaintained system has an account that's been locked out. The problem is that there are a variety of ways in which an account can be locked out, each with their own method of being unlocked.
It's not that the account is being locked improperly, just unexpectedly, but finding the correct lock to reset is difficult.
My most recent attack of this problem was on a SUSE system, and it turned out that the password had expired (which wasn't initially known because the login attempts were not through a system that provided that sort of feedback), and then also locked due to failed login attempts.
Is there a list somewhere of all of the different possible account locks and how to disable them? I'm intending for actual brokenness, such as home directory access problems, corrupt PAM libraries, etc., to be out of scope for this question.