Knowing the rules is necessary when playing golf.
An important part of learning how to play golf properly is familiarizing yourself with the etiquette and rules of the game. This can prevent you from making an unintentional mistake that results in receiving a penalty stroke or causes you to disrupt the play of others. Certain rules apply to each area of the course, including the putting green.
A player is not permitted to touch anything along the path the ball would likely take on its way to the hole. The exceptions are the following: removing obstacles that do not require the pressing down of turf, fixing a ball mark, measuring a shot, replacing a ball or placing a marker, or placing the putter in front of the ball while addressing it.
At the Flag
The ball cannot strike the flagstick while it is in the hole unless the shot originated off the green. If the flag is attended, the ball cannot be touched by the person holding the flag or by the flag when it is lifted as the ball approaches.
The player is allowed to make certain repairs on the green. For example, if there is a plug on the green from a previous hole placement, the player can smooth over the area. The player also can repair any damage caused by a ball from a previous shot, even if the player’s ball is not on the green. The player cannot repair the green in order to improve a ball’s lie.
A player is required to replace a ball marker or the ball if it is moved by accident while making a permitted green repair. The player is not assessed a penalty stroke as long as the movement occurs while making an eligible repair.