Coffee shop public washroom etiquette for millennials

...who don't seem to have been taught this stuff by their parents, teachers, etc.  f it's an all-gender public washroom, a CLOSED DOOR means that someone is on the other side of it.  Ipso fatso, you DO NOT rip said door off its hinges, breaking the lock mechanism, trying to get the door to open, nor do you batter the door in with your shoulder, catching that someone with their pants down and scaring the hell out of them. YOU KNOCK and wait long seconds for an answer.  Finally, when it's YOUR turn and you're finished doin' your business, DO NOT CLOSE THE DOOR when you exit this public washroom; leave the door ajar so that other patrons know it's available. —Am I Going Too Fast For You