Same with the sign on a certain airport I visited a number of times as a service engineer:

There was a hand full of cash with a stop sign over, obviously it meant "we do not accept bribes".

But for me it meant "this place have or have recently had a serious problems with bribery".

Same with: "We do not spit on the floor in this building".

Receiving bribes, soliciting bribes or declining bribes?

The variation of your example would be:

"If this community introduces a CoC, all participants start to suspect there were some incidents involving bigots and assholes in the community"

I don’t know why you’re being downvoted. When I was younger, seeing a bouncer guarding the entrance to a pub was a pretty decent proxy for that pub not being the kind of place I’d like to have a drink in.