A ball lying on any “closely mown area” through the green may, without penalty, be moved or may be lifted, cleaned and placed within six inches (150mm) of where it originally lay, but not nearer the hole and not in a hazard or on a putting green.
A player may move or place the ball once and after the ball has been so moved or placed it is in play.
Through the green, a ball embedded in its own pitch-mark in the ground, other than
sand, may be lifted without penalty, cleaned and dropped as near as possible
to where it lay but not nearer the hole.
The ball, when dropped, must first strike a part of the course
through the green.
“Closely mown area” means any area of the course, including paths through the rough, cut to fairway height or less.
“Through the Green” is the whole area of the course except (a) the teeing ground and putting green of the hole being played and (b) all hazards on the course.
Whilst Winter Mats are in use, all Summer Grass Teeing Areas are to be treated as Ground Under Repair. If a ball comes to rest on any such area, relief under the normal “Ground Under Repair” rules must be taken. The player must lift the ball and drop it, without penalty, within one club length of and not nearer to the hole than the nearest point of relief. The ball may be cleaned when lifted. (Rule 25-1b)