What does "Mind your p's and q's" mean?

Rebecca

This is a great question. "Mind your Ps and Qs" is an expression from the UK which generally means to mind your manners, mind your language, or behave properly. Here, the speaker is stating his intention to teach the others a lesson in manners. It is a casual phrase that is not used frequently. Ex. We don't condone violence in this bar. Mind your Ps and Qs.