What the heck is a forbidden archives?

I've normally been going around my day when ive been hearing signs of a forbidden archives and stuff.

heck, one time i was playing a game I like when it mentioned that "I should look for the forbidden archives."

ONE, i looked everywhere in the code, and i CANT find this at all

TWO, theres no documentation of this online, ANYWHERE

THREE, there isnt even just a "archives" in the game

if I can get it to occur again (the game does have some things changed by a value..) ill put a screenshot here

meanwhile ill update this with more finding of this and such.