Half Pint and Pint

These are the local denominations. The half pint on the left is Skrumpy
Jack (Hard Cider) and the pint is Guinness. The English have moved to
the metric system EXCEPT for the Pint. The Pint is 20 oz. and a
National Treasure! Two fun factoids: Arthur Guinness was from
England. "Mind your P's & Q's" is originally an English expression
meaning Mind your Pints and Quarts! Originally the way "Drink" was
served in England. After a few quarts an unscrupulous Land Lord was
likely to add an extra tally mark or two to the chalk board (your tab).
Thus overcharging their drunken patrons if they weren't minding their
Ps & Qs.