So this is an open thread to discuss any of those quirky cultural norms, behaviors, rules, etc. that aren't legally on the books in your city, but that most people still abide by, and can cause conflict when they aren't followed.
The idea for this thread came to me from the recent big snowfall we got walloped with. In chicago, as I'm sure exists in other northern cities, there's the tradition of "dibs" wherein if you dig your car out of street parking spot after a big snowfall, you can put lawn chairs, garbage cans, saw horses, traffic cones, pretty much anything in that spot when you leave it to reserve it for yourself for some unspecified amount of time.
Now, there is absolutely no law on the books that sanctions this "reserving" of parking spots after big snowfalls, yet in many many neighborhoods this behaviour is tolerated and followed. Many a conflict between neighbors has been had over people not respecting another person's "dibs" and about how much time "dibs" can still be claimed after a big snowfall.
Source:
https://www.huffpost.com/entry/chica...otos_n_6471978
So what about your city? Does it have any silly rules like the above that people pretty much follow and abide by even though they have no backing in law?