Combined Army Operations in Urban Terrain — FM 3-06.11 (FM 90-10-1)

Urban operations (UO) are operations planned and conducted in an area of operations (AO) that includes one or more urban areas. An urban area consists of a topographical complex where man-made construction or high population density is the dominant feature. Urban areas are the centers of finance, politics, transportation, communication, industry, society, and culture. Therefore, they have often been scenes of important military operations, both combat and noncombat.