Mud Rule (as at 26/6/16):
Any ball lying on through the green, with mud adhering to it, may be lifted, cleaned and placed within one card length, without penalty.
Process: The player must state to their marker that they intend to use the mud rule. The marker should, where possible, observe the player mark the location of the ball, clean it and replace it on the same spot. Once done so the ball is in play and cannot be lifted again.