United Kingdom law requires certain steps be taken to ensure that a pint of beer is indeed a pint. Though this can be achieved using so-called "metered dispense" (calibrated pumps), the more common solution is to use certified one-pint glasses. Until recently these had a crown stamp and number etched upon them, however EU directives have stated that the glasses instead now, must have PINT with the letters CE etched on them, for synchronisation in the European Union (although the Conservatives have campaigned to have dual markings of crown and CE). The number relates to the authority certifying the capacity of the glass. Selling beer in unmeasured glasses without using some other form of calibrated measure is illegal. Half-pint and one-third pint glasses are also available, and are subject to the same laws.
Despite this emphasis on accurately measured glasses, there is a practice of defining a pint of beer and lager as only 95 per cent liquid. It is common for drinkers to be served less than a full pint of liquid - either because too much of the glass is taken up by a foamy "head", or simply because the customer has been sold a short measure. This allows publicans to sell more pints of beer than the stated capacity of the cask or keg and hence save money. To counter this the British Beer and Pub Association have issued guidelines for bar staff to respect a customer who asks for a 'top up' to a full pint. At present, those selling "pints" up to ten percent short will not be prosecuted in the UK .
For those wishing to avoid this practice while still serving beer with a large head, "lined" or "oversized" glasses are available. These have a line near the top (usually labelled "pint to line") to which the beer should be poured, with the head forming above it. In the past a number of breweries supplied these glasses to their pubs; this is now rarely the case and lined glasses are found mostly at enthusiasts' events such as beer festivals, serious cask ale pubs, and breweries' own bars. The use of lined pint glasses in pubs is advocated by the Campaign for Real Ale.
In Canada, both British and US pint glasses are used.
In the United States, a pint is 16 fluid ounces. Recently (as of 2008), some restaurants have replaced 16-ounce pint glasses with 14 ouncers to which customers have objected.
In Australia it is common for "Irish pubs" to serve imperial pints (568 ml) whereas most other pubs will generally serve 425 ml glasses. This varies from state to state, see Australian beer glass sizes for a full explanation.
The Republic of Ireland also uses 568ml (i.e. an imperial pint) glasses, where legal metrology marks are used to show that a glass has passed inspection by the National Standards Authority of Ireland, a state-run body who enforce a number of standard rulings. Starting in 2006, the NSAI "pint" mark, a circle featuring two wavy lines, between which "PINT" is written, with a year mark (last two digits), and a three digit batch code either side; has begun to be phased out with a European standard "PINT"/CE logo stamp.
It is increasingly common to find pint glasses which contain markings on the base, very often these glasses are branded to one particular beer. The markings themselves are formed from small pits which aid in nucleation, allowing the gas within it to more readily release and thus preserve the head. Without the aid of these pits a regular pint glass will keep a head for only 3 or 4 minutes before appearing 'flat'. The markings come in a variety of styles ranging from a simple circular or square hatched pattern to more complicated branding messages.