Definition: An obstruction is defined a movable if it can be - without unduly delaying play, causing any damage or requiring unreasonable effort - moved.
A movable obstruction that affects stance or swing can be removed under the conditions above, and the stroke played. If the ball is in or on a movable obstruction, the ball can lifted, the obstruction moved, and the ball dropped (through the green or in a hazard) at the spot it had been resting. On the green, it can be placed. And of course, "no nearer the hole" applies.
Movable obstructions are covered in the rulebook in Rule 24.
Common Misspellings: Moveable obstruction
