A gill is indeed ¼-pint in S England, but if you ask for 'a gill' in a Yorkshire pub you will be given ½-pint. Many years ago I had a girlfriend from Keighley, Yorkshire, whose surname was Gill [a widespread local name] and her nickname at school had been "Halfpint", she told me.

Confusing, eh wot·wot!?

≈M≈

Even (not to drift) my cat Cleo admits to being confused.