When I was in middle-school, a rumor went around that you could make free long-distance calls by dialing 9-9-1 before the phone-number because it was some sort of phone-company code. I don’t know if that was true, if someone was trolling, or it was just a misunderstanding of stories about phreaking with the Cap’n Crunch whistle, but a bunch of kids tried it. I doubt it worked (I think I might have tried it from a payphone in the street once, but definitely didn’t get it to work), but enough kids in our school tried it with the pay-phone at school but did it wrong and dialed 9-1-1 instead of 9-9-1, that 911 complained to the school, and the principal had the phone removed. 🤦