When You Get Relief
You get relief from ground under repair when your ball, stance or intended swing is interfered with by the area. If any part of your ball or stance lies on the marked line, it is considered in the ground under repair. You may also take relief if you are on the putting
green and a marked area is in your line.
When dropping from ground under repair, you must take the nearest point of relief (stance) and one club length. Make sure you drop the ball no closer to the hole. The ball must be dropped from knee-height. This is a change from the previous rule where you were allowed to drop from shoulder height.
If you are still standing in the ground under repair after you dropped, you must drop again. Your ball is in play after you have dropped and there is no interference from the ground under repair.
In a Bunker
When part of a bunker is marked ground under repair, you must take relief at your nearest point within the bunker. If complete relief is impossible, the player may drop outside the marked bunker under penalty of one stroke. He must keep the point where the ball was between the hole and where he's dropping.
Playing from Ground Under Repair
It is not mandatory to drop from ground under repair. You always have the option to play a ball from ground under repair unless the golf course or committee prohibits it.