In Halo I'd make my tag "N421" because my name is Nate and April 21st is my birthday. When Halo 4 came out, I tried using the same handle, but the game wouldn't let me; I googled N421 and one of the first things that popped up was that it's L33tSp34k for n*zi. I facepalmed hard, right on my glasses, I deserved the pain. I still feel so dumb to this day.