P's and Q's

Many times i have heard the phrase 'Mind your P's and Q's" and consequently, many times i have wondered what the heck P's and Q's even were. These were a few possible explanations:


Pigs and Quails?
Pennies and Quarters?
Papayas and Quinces? (Imagine a lemon and a pear made a baby. That's what a quince would look like.)
Pies and Quiches?
Pentagons and Quadrilaterals?


But none of them made sense. so finally i decided to get on the good 'ol internet and look it up.

In English pubs, ale is ordered by pints and quarts. So in old England, when customers got unruly, the bartender would yell at them to mind their own pints and quarts and settle down. And That's where we get the phrase "mind your P's and Q's"