Used to be 0-9999, then like weird combinations like your initials and 2 numbers or 3 specific numbers AA-018 you MUST contact the govenors office and fill out the application. It's online, but I've applied like 3/4 times. I know someone who waited 8 years for a preferred plate. But it's a mute point because I'm understanding they won't let them out because the state won't submit vanity plates