3-25. Terrain management includes allocating terrain by establishing AOs, designating assembly areas, and specifying locations for units. Terrain management is an important activity during preparation as units reposition and stage prior to execution. Commanders assigned an AO manage terrain within their boundaries. Through terrain management, commanders identify and locate units in the area. The operations officer, with support from others in the staff, can then de-conflict operations, control movements, and deter fratricide as units get in position to execute planned missions. Commanders also consider unified action partners located in their AO and coordinate with them for the use of terrain.