Players should ensure that no one is standing close by or in a position to be hit by the club, the ball or any stones, pebbles, twigs or the like when they make a stroke or practice swing. Players should not play until the players in front are out of range. Players should always alert green staff nearby or ahead when they are about to make a stroke that might endanger them. If a player plays a ball in a direction where there is a danger of hitting someone, he should immediately shout a warning. The traditional word of warning in such a situation is "fore."
Golf Tips: Golf Etiquette and Safety
Today's Tuesday tip covers two subjects, etiquette and safety.
Clubs
Did you know that most golf accidents/injuries come from clubs striking players rather than golf balls hitting them? That's because players are not paying attention and someone gets whacked by a golf club when a another is taking practice swings. For safety always be sure you are clear of other players when swinging your club. It is not only safe, but good etiquette to stay nice and clear of players who are swinging their clubs.
Balls
Golf balls can travel upwards of 200 miles per hour. As someone who has been hit by one three times, I can personally verify that getting hit by a small hard ball traveling 150-200 miles per hour is not pleasant. It is very important for players who are about to play a shot to make sure that they are doing so when it is safe. Players must make sure that the group in front of them is out of range and that nobody nearby is in danger. (Insert "people are always in danger when I hit" joke here)... It is also very important to make sure that grounds crew (course employees, maintenance workers etc) are aware.
On the flip side, it is also important for players who are not currently hitting to make sure they're not in danger. Players must always be aware of what is going on around them and be careful not to stand in the way of another player's golf shot or swinging golf club. Once again, good etiquette and more importantly, safe.
From the USGA: