Or drop the alpha chars altogether and just go numeric. It worked for CompuServe. Everyone's ID was an octal number. 72167,4531 for example.
That way there is no overlap, and nobody is slighted when they find out that their name is taken.
That way there is no overlap, and nobody is slighted when they find out that their name is taken.
ICQ uses a number, but yeah, how many people still use it?
Plus, now that the identifier carries no meaning, you can't type "@realdonaldtrump ..." and expect people to know who it refers to, you'd have to type "@aae0450, Donald Trump ...".