Wetherspoon's are offering beer in thirds of a pint during their current beer festival. Well, to be honest, I think they're offering three beers, each in a 1/3 pint glass, rather than individual thirds of a pint, but anyway....
What caught my eye was that the 1/3 pint glasses appear to be line measures. They are the new-fangled Euro-glasses, i.e. stamped with the CE logo rather than the Crown, but they have a little smudged line just above the stamp.
Are they line measures? If so, why don't they say so? Crown stamps say "HALF PINT TO LINE" or whatever; anything else is an implied brim measure.
And if these glasses are brim measures, what's the line for?