I came across an interesting bit of beer lore today. Apparently the saying “Mind your Ps and Qs” is derived from an accounting method used by English tavernkeepers during the 1700s. To keep track of each customer’s tab, the keeper would record their orders on a slate with the letters P and Q at the top. The P was for Pints and the Q for Quarts. When it came time to pay, customers had to mind their Ps and Qs or face being overcharged by an unscrupulous tavernkeeper! From Phillips, Glen C. On Tap: The Odyssey of Beer and Brewing in Victorian London-Middlesex.