As the story goes, ‘X’s were a medieval Yelp review system for traveling royals. Courts in Europe would dispatch a statesman of suds to sample beer along a planned travel route, and he would mark one ‘X’ on the sign of an establishment with average beer, two for a better brew, and three for an essential stop. … And that’s why the San Antonio Brewing Association used its “xXx” branding when it bought the City Brewery in the late 19th century—and why its signature Pearl Beer, o