it dont just need to be a y regger

you could have a p ie bee7p or a f ie... bee7f

you can't put one single letter followed by 1,2 or 3 digit numbers and 3 letters as it ,makes it a yreg or newer 2001 onwards and you can't do that.

anything 1982 ie aaa1y or older ie aaa1x or aaa1w etc etc.
gottit eh!