Rule 21. Cleaning Ball
A ball on the putting green may be cleaned when lifted under Rule
16-1b. Elsewhere, a ball may cleaned when lifted except when it has
been lifted:
a. To determine if it is unfit for play ( Rule 5-3)
b. For identification (Rule 12-2), in which case it may be cleaned
only to the extent necessary for identification; or
c. Because it is interfering with or assisting play
If a player cleans his ball during play of a hole except as provided
in this Rule,he shall incur a penalty of one
stroke and the ball, if lifted, shall be replaced. If a player
who is required to replace a ball fails to do so, he
shall incur the penalty for breach of Rule 20-3a, but no additional
penalty under Rule 21 shall be applied.
Exception: If a player incurs a penalty for failing to act in accordance
with Rule 5-3, 12-2 or 22, no additional penalty under Rule 21 shall
be applied.