> On Jun 5, 2018, at 1:50 AM, Barry Leiba <barryleiba@xxxxxxxxxxxx> wrote: > >> To see why consider comparing my first name as I usually write it >> (Nicolas) vs. how it should be written (Nicolás). The two strings >> should compare as not equivalent. But the two ways to write the second >> form (with the ´ precomposed vs. decomposed) should compare as >> equivalent (because they are). The above is a simple statement about *equivalence* > - does that mean that it's OK to have "nicolas" and "nicolás" as two > different usernames assigned to two different users? They are not equivalent, whether assigning both is a good idea is an entirely separate question. > - what about handling of "ä" vs "ae"? They are not equivalent. This is confusability question, not an equivalence question. > Do we want to avoid assigning > "käse" and "kaese" as distinct usernames? Ditto. > These are only some of the reasons it's difficult. And the number of > people who stand up and say, "oh, just <do this> and the problem is > solved," demonstrates that too too too many people *think* they > understand... and don't. Or do, but the participants are talking past each other... Natural language issues are messy, and necessitate trade-offs, which trade-offs to make can be the subject of much debate. For example, in EAI, I find the decision to introduce non-identity content-transfer-encodings of composite MIME parts to be far more problematic than the problem it is intended to solve. I wasn't around for the discussion, and probably would not have been able to change the outcome, but one way or the other someone would have had to walk away unhappy... (an alternative would introduce punycode encoding of localparts and break the sacrosanct rules about local parts being only understood at the destination, pick which axioms to violate, ... at least one). -- Viktor.
