The mandatory gratuity American restaurants and bars add to the bill of foreign customers, particularly Europeans, who don't understand or willfully ignore American tipping customs. Also known as the English Tax, Australian Tax, etc.
Bartender 1: Oh shit, another big group of English people. The last time I got stuck serving their kind they stiffed me on a $200 tab.
Bartender 2: Just hit them with the European Tax, dude.