MCRP 12-10B.1, page 116

during displacements. Movement is conducted during night or periods of reduced visibility. (b) Defense. Artillery is positioned on the friendly outskirts of the built-up area. Artillery displaces along predetermined routes to avoid traffic congestion. (3) Delivery of Fires. The commander, in coordination with the fire support coordinator (FSC), considers the following when planning fire support in a built-up area: (a) Target acquisition may be more difficult because of the increased cover and concealment afforded by the terrain. Ground observation is limited; therefore, FOs should be placed near tops of buildings. (b) For targets in defilade, fire may be adjusted laterally so that the rounds impact on the street perpendicular to the observer's position. Airburst rounds are more suitable for this adjustment. Adjustments may have to be made by sound. When rounds impact on a perpendicular street, they are adjusted for range. When the range is correct, a lateral shift is made onto the target and the observer fires for effect. (c) Special consideration must be given to shell and fuze combinations when effects of munitions are influenced by buildings. These include: Careful use of variable time is required to avoid premature arming. HE ammunition with impact or delay fuzes may create unwanted rubble. The close proximity of enemy and friendly forces requires careful coordination. White phosphorus (WP) may create unwanted fires and smoke. Fuze delay should be used to penetrate fortifications. Illumination rounds can be effective. However, friendly positions should remain in shadows and enemy positions should be highlighted. Tall buildings may mask the effects of illumination rounds. HE/variable time, HE/time fuze, and improved conventional munitions are effective for clearing enemy positions, observers, and antennas from rooftops. Swirling winds may degrade smoke operations. FASCAM may be used to impede enemy movements. FASCAM effectiveness is reduced when delivered on a hard surface. Military Operations on Urbanized Terrain 4-3