cainxinthIs it a pint?
I'm from Ireland, where filling beers precisely up to the brim is practically a religion, & many barmen will even take the glass back & top it up if they see the head diminishing too quickly in the space of time it takes you to pick the freshly poured pint up.
One thing that always struck me as odd is how the culture is seemingly the opposite of this in apparent beer meccas like Belgium - not only are the glasses typically much smaller (this is fine) but they also leave massive gaps at the top. The glass capacity is never treated as being close to the rim at all.
I remember watching the cornetto trilogy ( https://en.wikipedia.org/wiki/Three_Flavours_Cornetto ) and always wondering why on earth they fill up the glasses up to the brim. It is uncomfortable to transport this way and not spill beer.
When CAMRA was new in the early 1970s, they started a campaign for oversize glasses holding a pint to the line instead of a pint to the rim, so that there would be space for a pint of liquid and a head in the glass. The big breweries hated this idea and mounted a reactionary campaign arguing things like it would be too expensive to replace all the glasses, or serve customers the full measure they had paid for. (My father was a new recruit at Guinness and sadly one of his early tasks was the pint-to-brim campaign.)
I no longer drink in pubs but in my neck of the woods, the pubs that specialised in cask ale often had lined glasses.
The problem was that many people insisted on the glass being filled to the brim, because they felt they were being short changed. So it solved one problem but created another.