For just over 300 years (until the implementation of the Measuring Instruments Directive on 1-Nov-2006) beer glasses in Britain were marked with a “Crown” to show they contain exactly 1 Pint. Perhaps an effect of our vote to leave the EU on 23-Jun-2016 will be a return of the Crown mark on beer glasses.
The marking was introduced by act of parliament in 1698 (during the reign of William III) and every pub had a notice stating that beer could only be sold in full pints or quarts and the drinking vessels (whether they are made of glass, pewter, leather, wood, or horn) must marked with WR or a Crown.
The number under the crown identifies the maker, immediately before the CE mark replaced the crown almost all beer glasses bore the number 2043 indicating it is made in France by JG Durand & Cie of Arque (near Calais).
Our glass industry has now revived. If a CE marked beer glass bears the number 0846 it has been verified to contain 1 pint by Bury Trading Standards and it is likely to have been made in the UK.