I used to work with a guy who was addressed exclusively by his nickname. Sometimes I wonder if his work contract sported his name or nickname.

Funnily he was one of our union reps in the company, one day we had a big assembly with a couple of union officials, at the end the officials thank each of our three reps: "ok, so thanks to [name], [surname], [name], [surname], and.... [guy's nickname], sorry I don't know your actual name."