Best thing would do is to have a single field for name and surname and other legal variations. Like many pointed out the cultural differences are way too many

Best thing would do is to have a single field for name and surname and other legal variations. Like many pointed out the cultural differences are way too many to pull up with more than one field and manage them all algorithmically. That's a recipe for disaster when the culture changes the way they use the identity. I'm a developer and I'm not gonna fall for that.