Why not just have a single field for "your name as it appears on your identity document"? Or do the various airline systems expect the name to be split into separate fields depending on the locale?

I've always found it weird how broken this is. Some US airlines have separate entry fields for first, middle, and last names. But then they jam it together on the boarding pass as "Last, Firstmiddle" (yes, with first and middle mashed together, and middle lowercased). That of course doesn't match my ID, but I've never had a problem traveling, even when I sometimes leave out my middle name entirely. (I guess I get less scrutiny most places since I'm an American white male.)