I learned that part of flag etiquette and law back when I was a Brownie. We couldn’t participate in the flag ceremonies until we could pass the quiz from our leaders. I don’t remember all the questions. I do remember being quizzed on rules about flying the flag at night (legal or not, what makes it so), which end to start folding the flag from, how to dispose of a flag, and the ever present when to salute.
I thought everyone knew these rules. Should realize not everyone gets this drilled into them. It’s a shame that it isn’t.