Its a generic question, usually a 4 digit sequence as far as I have seen. I have a few, the numbers differ.
Just interested in what they represent, if anyone knows. A specific example doesn't change the answer as it would apply to all...
But in any case, one of mine is 0537, others are not handy and boxed away. Have pics of a 0487, 2407.
I thought maybe date, with the 7 and 8 as end digits, but 3 prefix numbers to that don't cover month year, need 4...