what do the numbers on the caseback signify? i mean each set of numbers?

also are the numbers exactly the same on every watch, or is it just the last few that changes per watch or series, or.....?

i have been hunting the internet for caseback pics, but i haven't found any as of yet, other than the one on otd and a dealer site which the numbers matched up exactly....that's what got me going, on trying to figure it out. a big thanks in advance for any attempts, educated guesses, or answers.

j.h.