When a player’s ball lies on the putting green, there is no penalty if the ball or ball marker is accidentally moved by the player, his/her partner, his/her  opponent or any of their caddies or equipment. 

The moved ball or ball marker must be replaced as provided in Rule 18-2, 18-3 and 20-1. 

The Local Rule applies only when the player’s ball or ball marker lies on the putting green and any movement is accidental. 

If it is determined that a player’s ball on the putting green was moved as a result of wind, water or some other natural cause such as the effects of gravity, the ball must be played as it lies from its new location. A ball-marker moved in such circumstances is replaced.