Rule 42 (now Rule 5.1 and Rule 44 in the 2008 guide) is a rule of the Gaelic Athletic Association (GAA) which in practice prohibits the playing of non-Gaelic games in GAA stadiums. The rule is often mistakenly believed to prohibit foreign sports at GAA owned stadiums. However, non-Gaelic games such as boxing and American football did take place in Croke Park before Rule 42 was modified.