What are all of the allowable characters for people's names? [closed]

There's good article by the W3C called Personal names around the world that explains the problems (and possible solutions) pretty well (it was originally a two-part blog post by Richard Ishida: part 1 and part 2)

Personally I'd say: support every printable Unicode-Character and to be safe provide just a single field "name" that contains the full, formatted name. This way you can store pretty much every form of name. You might need a more structured storage, but then don't expect to be able to store every single combination in a structured form, as there are simply too many different ones.

Whitelisting characters that could appear in a person's name is the wrong way to go, if you ask me. Sure, [A-Za-z] is a fair starting point, but, as you said, you get problems with "European" names. So you map all the umlauts, circumflexes and those. What about Chinese names? Japanese? Indian? Hebrew? You're entering a battle against wind turbines.

If you absolutely must check the validity of someone's name, I'd suggest doing a modest blacklist of certain characters. Braces, mathematical characters, some punctuation and such might be safe to ignore. But I'd be cautious, if I were you.

It might be best to just accept whatever comes in. UTF-16 should be today's overkill character set, that should be adequate for some years to come.

Edit: As for your question about name length and amount of names. If you really want people to write their real and complete names, I guess the only foolproof answer to both of those questions would be "infinite". Not being able to whip out any real examples for human beings, but surely there are analogous examples for humans as the native name for the city of Bangkok.

I don't think there's a definitive answer. After all, some people have names that can't even be expressed in UTF-16...

There are some odd people out there, who will give their kids the craziest of names, including putting in weird punctuation, accents that don't exist in their own language, etc.

However, you can place arbitrary restrictions on your database. If you want to you can insist on 7 bit ASCII names. It's slightly rude to users, but they'll live with it. It certainly makes searching easier.

My colleague's daughter is named Amélie. But even some (not all!) official British government web sites ("Please enter the name exactly as shown on the birth certificate") won't accept the unicode, so he has to use 'Amelie' instead.