"If a ball is moved at rest by something that is not part of the game, there is no penalty and the ball must be put back.
Note: It is a question of circumstances whether a ball has been moved by something that is not part of the game. In order for this rule to apply, it must be known or virtually certain that something not part of the game has moved the ball. In the absence of such knowledge or certainty, the player must play the ball as it lies or, if the ball is not found, proceed in accordance with Law 27-1. (The player's ball at rest moved by another ball - see Law 18-5.)².
Status: 2018
