Basic Rules
Lost Ball / Out of Bounds
If you cannot find your ball after looking for it for 3 minutes, or if you cannot unequivocally identify it as your own, it is classed as lost. Take a drop from where you hit your last shot. 1 shot penalty.
The same applies for a ball out of bounds.
If
you suspect you have lost your ball or hit it out of bounds you can (and
should) hit a provisional ball. Play that ball until the approximate position
where you believe the original ball is. If you cannot find your original ball
play your provisional with a 1 shot penalty.
Lost Ball / Out of Bounds - Optional rule 

Moveable Obstructions
Bottles, cans, signs, stakes (yellow, red, blue) or other artificial obstructions can be removed without penalty. If the ball moves as a result, put it back without penalty.
Even if the ball is lying in or on the obstruction, the obstruction can be removed. The ball is then to be dropped at its original position.
Note: removing an out of bounds post is never permitted (2 stroke penalty).
Immovable Obstructions
Roads and paths with an artificial surface or other fixed, artificial objects entitle you to free relief if they interfere with the balls lie, your stance or swing, but NOT if they interfere with the line of play.
To take relief, locate the nearest point where you can take your stance and swing without interference from the obstruction and drop the ball within one club length.
Abnormal Ground Conditions
The following are examples of abnormal ground conditions:
casual water (visible puddles or water appearing when you stand on it), machinery tracks and wheels marks, scratchings or holes caused by animals, grass or other material piled up to be removed, and holes made by the greenkeepers.
Take
a free drop within one club length of the nearest point of relief.
Unplayable Lie;

Water Hazards (Penalty Areas)
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Dropping ;
Relief from Abnormal Ground Conditions