The tournament is commonly known as the “Guinness Six Nations,” and this is the name by which the International Rugby Board recognizes it. This is due to the fact that, as of the 2019 tournament, Guinness has been the tournament’s official sponsor. Given the regular turnover of tournament sponsors, however, the Six Nations is typically just called by its generic name. For one of the six countries, the Guinness name isn’t used because French law prohibits alcohol companies from sponsoring sports.