Has there ever been an official (A)D&D product in which character levels (as per the rules governing the game) were recognized and utilized to some degree in-game, within the game world, by the actors of the game world? If so, which product, for which edition of the game?
See, I think that intelligent beings should, with time, connect all the dots, and recognize that certain abilities possessed by certain people form well-defined classes and can be mapped to distinct tiers of advancement. (As far as I can remember, Terry Pratchett had wizards on the Discworld who recognized numbered "circles" of advancement. :)) In fact, I find it somewhat puzzling when long-lived, and thoroughly learned beings of high IQ and WIS fail to see and to use the big picture.
Note, please, that I do realize this is an obvious twist on a question I myself asked years ago. Note also, however, that this Q here has quite a different focus, and is not limited to a single edition. Apparently, the broader issue keeps nagging me. :)