> I'm curious if anyone can think of any other non-alphabetic characters used in legal names around the world, in other scripts?

Some Japanese names are written with Japanese characters that do not have Unicode codepoints.

(The Unicode consortium claims that these characters are somehow "really" Chinese characters just written in a different font; holders of those names tend to disagree, but somehow the programmer community that would riot if someone suggested that people with ø in their name shouldn't care when it's written as o accepts that kind of thing when it comes to Japanese).

Ha, well I don't think we need to worry about validating characters if they can't be typed in a text box in the first place. ;)

But very interesting thanks!