Draught beer and cider can only be sold in Imperial pints.
However, people have to be careful with the trick question which is
"Do you want bottled or draught?"
Bottled beer, cider or whatever does not have to be supplied in imperial and can be any size that it wants to be.
Normally, you will be supplied 500ml or if you are unlucky 330ml.
This should be given to you in a uncalibrated glass.
Draft beer or cider should be served in a certified glass which were marked with a Crown from 1699 until 2006.
As the EU no longer authorised the use of the Crown, it was replaced by only CE markings from 2006 declaring that it is a British Imperial pint.
Don't anyone start me off about the Gill measure.
