i know the set numbers 7655 6311 e.c.t
re reading the OP it doesn't seem clear 'll rephrase it
how does Lego come up with the numbers on the box, using the example of the clone BP is the 7 the year, 6 the lego system ID, 55 the 55th kit released this year
(note: i know the numbers -> reasons don't make sense but i was making it up)
EDIT: Doctor Sinister replied while i was posted and thanks for the answer :) the sort of thing i was talking about