I was told that the P\'s \'n\' Q\'s thing came about, because; minding one\'s manners included saying \"Please\" and \"Thank-you\". \"Thank-you\", sounding like \"Thang-Q\".Originally posted by Hieronymus
I thought that mind your q\'s and p\'s came from the early days of movable type. I looked it uq on wikiqeia.org and they mentioned the qints and puarts origin as being idiomatic to the UK.
So, at least three plausible origins for the same phrase. Any others?