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.)