Rule 24: Obstructions.

Definition.

The "nearest point of relief" is the reference point for taking relief without penalty from interference by an immovable obstruction, an abnormal ground condition or a wrong putting green. It is the point on the course nearest to where the ball lies that is not nearer the hole, and where, if the ball were so positioned, no interference by the condition from which relief is sought would exist for the stroke the player would have made from the original position if the condition were not there. Note: In order to determine the nearest point of relief accurately, the player should use the club with which he would have made his next stroke if the condition were not there to simulate the address position, direction of play and swing for such a stroke. An "obstruction" is anything artificial, including the artificial surfaces and sides of roads and paths and manufactured ice, except:
(a) Objects defining out of bounds, such as walls, fences, stakes and railings;
(b) Any part of an immovable artificial object that is out of bounds; and
(c) Any construction declared by the committee to be an integral part of the course.
An obstruction is a movable obstruction if it may be moved without unreasonable effort, without unduly delaying play and without causing damage. Otherwise it is an immovable obstruction. Note: The committee may make a local rule declaring a movable obstruction to be an immovable obstruction.