Rules of golf not one of the numbered rules, is found in the R&A rule book's inside front cover: "Play the ball as it lies, play the course as you find it, and if you cannot do either, do what is fair. But to do what is fair, you need to know the Rules of Golf." In addition to the rules, golf adheres to a code of conduct known as etiquette, which generally means playing the game with due respect for the golf course and other players. Etiquette is often seen as being as important to the sport as the rules themselves. Before
Nine-ball to sweep the sport of nine-ball in the mid-1980s, restricted the push-out option to once per game and only to the inning immediately following the break. This change profoundly affected the way the game was played. By about 1990 this new push-out rule had become ubiquitous and it and any additional rules appended to it were collectively referred to as "" rules, so called because of the supposed US state of origin and the speeding up of the game. Today, Texas express push-out rules dominate the way nine-ball is played and is the variant incorporated into the official rules maintained