Card room etiquette is a bit difficult to conceptually know about and that is why there are a lot of things that people need to know. While most of these situations are not likely to come up anytime soon in your card room, knowing what the rules are might help you very much. Just as a final note, these card room rules are not universal, but rather are modal; the ones that are most likely to be in place in your card room just from natural statistics. The actual rules in your card room might differ.