How stupid! The tag on my Taurus is also a FL Air Force personalized tag, reads A1MH1 (Aim High) - AIMHI was taken. That was the slogan when I enlisted. Had no problem getting it.
However, when I was stationed in NC, the State absolutely denied anything i tried to do with the number 13... either in munerical or spelled formats. It conflicted with the State numbering system, even when used with other letters...