Moveable Obstruction

It seems that there is still some confusion between what is an Loose impediment and an movable obstruction, some exmaples below

Loose Impediments (natural) Movable Obstruction (artificial)
stones bunker rakes
leaves other players’ golf clubs
branches and twigs stakes (except out of bounds)
pine cones signage and ropes
dung and droppings bottles and cans
insects score cards
worms and their casts pens and pencils
spiders and their webs paper, tissues
half-eaten fruit plastic bags
fruit skins packets and boxes
ant hills toys
dead birds and animals match sticks or cigarettes
aeration plugs abandoned balls
clods of earth loose stones from a wall
gravel wood manufactured into planks
crushed shells cables
wood chips doors or windows

Note that sand and loose soil are only loose impediments on the putting green.

Movable obstructions can be removed anywhere on the course, including when the ball lies in a hazard, without penalty if the ball moves during the removal, but MUST be replaced.

If the ball lies in or on the obstruction, the ball may be lifted and the obstruction removed. The ball MUST then be dropped, or on the putting green placed, as near as possible to the spot directly under the place where the ball lay in or on the obstruction, not nearer the hole. 

However, if a player’s ball lies in a bunker it is not permitted to remove any loose impediment from that bunker.  With the exception when a Local Rule which states, “Stones in bunkers are movable obstructions”, is inforce.