MCRP 12-10B.1, page 207

c. A chimney or other protruding structure provides a base from which a sniper position can be prepared. Part of the roofing material is removed to allow the sniper to fire around the chimney. He/She should stand inside the building on the beams or on a platform with only his/ her head and shoulders above the roof (behind the chimney). Sandbags placed on the sides of the position protect the sniper’s flanks. d. When the roof has no protruding structure to provide protection, the sniper position should be prepared from underneath on the enemy side of the roof (Figure A-58). The position is reinforced with sandbags, and a small piece of roofing material should be removed to allow the sniper to engage targets in his/her sector. The missing piece of roofing material should be the only sign that a position exists. Other pieces of roofing should be removed to deceive the enemy as to the true sniper position. The sniper should be invisible from outside the building, and the muzzle flash should be hidden from view. Figure A-58. Sniper Position e. Some rules and considerations for selecting and occupying individual firing positions are: (1) Make maximum use of available cover and concealment. (2) Avoid firing over cover; when possible, fire around it. (3) Avoid silhouetting against light-colored buildings, the skyline, and so on. (4) Carefully select a new firing position before leaving an old one. (5) Avoid setting a pattern; fire from both barricaded and unbarricaded windows. (6) Keep exposure time to a minimum. A - 46 MCWP 3-35 .3