<P> In the United Kingdom , draught beer must be sold in Imperial measure ( see Pint § Effects of metrication ) . United Kingdom law requires certain steps be taken to ensure that a pint of beer is indeed a pint . Though this can be achieved using `` metered dispense '' ( calibrated pumps ) , the more common solution is to use certified one - pint glasses . Until recently these had a crown stamp indicating that the certification had been done by an agency of the Crown . The number etched upon the glasses stands for the manufacturing company or site . Most pint glasses used in the United Kingdom today have actually been produced in France . </P>
what does the m number mean on a pint glass
the manufacturing company or site