(Taken from the official R&A Model Local Rules (randa.org))
Model Local Rule E-4; If a player’s ball lies in or touches an aeration hole:
(a) Ball in General Area. The player may take relief under Rule 16.1b. If the ball comes to rest in another aeration hole the player may take relief again under this Local Rule.
(b) Ball on Putting Green. The player may take relief under Rule 16.1d. But interference does not exist if the aeration hole only interferes with the player’s stance or area of intended swing or, on the putting green, on the player’s line of play.
Model Local Rule E-5; When a player’s ball has not been found or is known or virtually certain to be out of bounds, the player may proceed as follows rather than proceeding under stroke and distance.
For two penalty strokes, the player may take relief by dropping a ball in this relief area** (see Rule 14.3):
Two Estimated Reference Points:
(a) Ball Reference Point: The point where the original ball is estimated to have:
- Come to rest on the course, or
- Last crossed the edge of the course boundary to go out of bounds……………”
** Basically place the ball two club lengths onto the fairway no nearer the hole for a two shot penalty.