Before traveling to a golf course, a conscientious golfer will make sure he has all of his equipment. Items such as clubs, golf balls, tees and ball markers are obvious requirements, but a felt pen in a bright color, such as purple, can also be an important piece of equipment. The pen may be used to mark your ball so you can positively identify it as yours when you locate it in a hazard or deep rough.
Marking the Ball
You may draw a mark on your ball to help you identify it, according to Rule 12-2 of the United States Golf Association’s Rules of Golf. While Rule 5-2 of Rules and Decisions bans golfers from applying “foreign material” to a ball, Rule 5 notes that “Markings applied to the ball by the player (e.g., using a felt-tip pen) are not contrary” to Rule 5-2. A purple dot provides a good way to identify a ball once it is located, or to distinguish it from another player's golf ball. Rule 6-5 of Rules and Decisions goes so far as to state, "Each player should put an identification mark on his ball."
Playing the Correct Ball
There’s no excuse for playing the wrong ball. Rule 12-2 of Rules and Decisions states: “The responsibility for playing the proper ball rests with the player.” The general penalty for violating Rule 12-2 is the loss of the hole in match play or a two-shot penalty in stroke play.
Locating the Marked Ball
If you hit the ball into a hazard, the purple dot you added won’t do you any good if you can’t see the ball. Rule 12-1 of Rules and Decisions describes methods a golfer may use to search for her ball in various hazards. For example, a golfer may bend long grass, bushes or other plants as long as she neither improves the ball’s lie nor the area in which she’ll set up to hit the ball. If she’s in a bunker, she may move some sand while identifying the ball, but she must re-create her lie afterwards.
Lifting the Marked Ball
Under Rule 12-2, a player may lift a ball -- if it is necessary to identify it -- without incurring a penalty. However, the golfer must first inform either his opponent or his marker, then he must mark the ball’s position before lifting it. If the ball is his, he may not clean it and must return the ball to its original lie.