There is no reason to require any particular comparison algorithm. One application is going to compare them the same way every time. Two different applications may reach different conclusions about two equivalent identifiers, but nobody cares because AT WORST the result is a bit of inefficient use of storage.
The guidance, if any, should simply state that identifier constructs must be unique. It is not our responsibility to prevent people from assigning the same (equivalent) identifiers to two different resources, nor do I care how many errors occur when they violate such a basic requirement.
....Roy
