You joke, but when a customer wants to give your company their money, it is our duty as developers to make sure their names are valid. That is so business critical!
What are “invalid names” in this context? Because, depending on the country the person was born in, a name can be literally anything, so I’m not sure what an invalid name looks like (unless you allow an `eval` of sorts).
The non-joke answer for Europe is extened Latin, dashes, spaces and apostrophe sign, separated into two (or three) distinct ordered fields. Just because it's written in a different script originally, doesn't mean it will printed only with that on your id in the country of residence or travel document issued at home. My name isn't written in Latin characters and it's fine. I know you can't even try to pronounce them, so I have it spelled out in above mentioned Latin script.
Non-joke answer for Europe is at least Latin, Greek or Cyrillic (български is already one of the official EU languages!). No reason to treat them differently, just don't allow for mixing them so you won't get homoglyphs. EURid (.eu-NIC) gets it mostly right I believe.
Prince: "Get over yourself and just use your given name." (Shockingly, his given name actually is Prince; I first thought it was only a stage name)
Musk: Tell Elon to get over his narcissism enough to not use his children as his own vanity projects. This isn't just an Elon problem, many people treat children as vanity projects to fuel their own narcissism. That's not what children are for. Give him a proper name. (and then proceed to enter "X Æ A-12" into your database, it's just text...)
