This surprised me. A lot, actually.
I know that you don't have registry offices like we have.
But I'd thought that there was some kind of "legal identification" when you do something 'official'. (Baptism is something religious here - no authority bothers about what is written in those certificates, besides church authorities who want to see the birth certificate.)
So you can marry legally under Whatswhoevername, get a driving licence under a different name, marry with your third, change Christian, middle, last names - and no-one really bothers?