Conforming Ball Must Be Played. In making each stroke, a player must use a ball that conforms to the requirements in the Equipment Rules.
A player may get a conforming ball to play from anyone else, including another player on the course.
Deliberately Altered Ball Must Not Be Played. A player must not make a stroke at a ball whose performance characteristics have been deliberately altered, such as by scuffing or heating the ball or by applying any substance (other than in cleaning it).