Please, please tell me you're kidding.
Nope... No clue why 68OU1 would be considered rude. Porn reference? Is it some reference to OU and a game they lost or something? Guess I'm not a real OKIE yet (mom just smiled down on me from heaven - she was a born and raised hard core and true blue Texan who I swear smacks me from the grave every time I grudgingly admit to being an OKIE).