Yeah, Texas only had vanity YOM plates available during 1985. Standard plates used the year/month stickers. All of the vanity plates I found had weird thicker letters or numbers at random. In this case it was the C and A. I think they chose the wrong prison to get uniform painting.
The cool thing about running YOM plates is that you don't have to have the stupid registration stickers on the windshield. If you look closely there's a small tag affixed on the plate bolt up in the corner that gives the actual registration expiration info.