What term describes the line that delineates surface areas for coordination and deconfliction between adjacent units?

• A. Boundary
• B. Phase Line
• C. Reconnaissance Handover Line
• D. Observation Post

Answer: (A)

Boundaries establish where one unit’s surface area ends and the next begins, providing a clear line for coordination and deconfliction. This demarcation helps prevent overlaps, reduces the risk of friendly fire, and guides planning for maneuver, fires, and support so adjacent units operate in their assigned space without interference.

A phase line, by contrast, is about coordinating movement and actions over time or across zones rather than defining the exact extent of each unit’s surface area. A reconnaissance handover line designates where responsibility for reconnaissance tasks transfers between units, not the general boundary between units. An observation post is a fixed surveillance position, not a line separating adjacent units’ areas.