What does this mean?

[skankywitch]

I have added a picture on my profile page of dd's new pony. I have never seen a freeze mark like this, anyone know what it is/means?
All our others are freeze marked but all along their backs and with more letters/numbers. In case it's hard to read it says 62b.

Have you tried contacting freeze mark companies? Or perhaps posting on a horse site? You know what horsey people are like, someone always knows someone that knows something

Good luck