text: Tactical Control Measures
  Limit of Advance
  A-53. The limit of advance is a phase line used to control forward progress of the attack (ADP 3-90). A LOA
  is a restrictive control measure because the attacking unit does not advance any of its elements or assets
  beyond the LOA, but the attacking unit can push its security forces to that limit. Units can employ direct and
  indirect fires beyond the LOA. A LOA is typically established by a higher echelon headquarters.
  Commanders usually select linear terrain features, perpendicular to the direction of attack, on the far side of
  the objective as LOAs because such terrain features are easily identifiable. They employ LOAs to prevent
  overextending the attacking force and to reduce the possibility of fratricide and friendly fire incidents by fires
  supporting the attack. They position LOAs far enough beyond their objectives to allow their units to defend
  the objective. A LOA prevents units from exploiting success and launching a pursuit; therefore, commanders
  should only use LOAs if they do not want to perform an exploitation or pursuit. A forward boundary is always
  a LOA, but a LOA is not necessarily a forward boundary. In fact, a LOA and the unit’s forward boundary
  should rarely coincide because of the resulting limitations that a forward boundary places on supporting fires
  beyond the forward boundary. Figure A-25 on page A-14 shows PL BASIL used as a LOA.
  Line of Departure
  A-54. In land warfare, the line of departure is a line designated to coordinate the departure of attack elements
  (JP 3-31). The purpose of the LD is to coordinate the advance of the attacking force so that its elements strike
  the enemy in the order and at the time desired. The LD also marks where the unit often transitions from
  movement to maneuver. Commanders can also use it to facilitate the coordination of fires. Generally, it
  should be perpendicular to the direction the attacking force will take on its way to the objective. Friendly
  forces should control the LD. Commanders analyze the terrain before designating an LD. Different units have
  different movement rates on leaving their assembly areas based on their inherent mobility characteristics and
  the terrain traversed. Commanders consider these different characteristics when establishing an LD to prevent
  these differences from affecting the synchronization of the operation. When possible, commanders select the
  LD so that the terrain the attack unit traverses before crossing the LD provides sufficient cover for the
  attacking unit’s final deployment into a maneuver formation before crossing the LD. In many cases, the LD
  is also the LC because the unit in contact is conducting the attack from its current positions. Figure A-25 on
  page A-14 depicts PL JOHN as a combined LD and LC.
  Objective Rally Point
  A-55. The objective rally point is an easily identifiable point where all elements of the infiltrating unit
  assemble and prepare to attack the objective (ADP 3-90). It is typically near the infiltrating unit’s objective;
  however, there is no standard distance from the objective to the objective rally point. It should be far enough
  away from the objective so that the enemy will not detect the infiltrating unit’s attack preparations.
  Point of Departure
  A-56. The point of departure is the point where the unit crosses
  the line of departure and begins moving along a direction of
  attack (ADP 3-90). Units conducting reconnaissance and
  security patrols and other operations in a low-visibility
  environment commonly use a point of departure (PD) as a
  control measure. Like the LD, it marks the point where the unit
  transitions from movement to maneuver under conditions of
  limited visibility. Figure A-28 depicts PD 7.
  Figure A-28. Point of departure 7
  Probable Line of Deployment
  A-57. A probable line of deployment is a phase line that designates the location where the commander intends
  to deploy the unit into assault formation before beginning the assault (ADP 3-90). Commanders at battalion-
  sized and smaller units primarily employ PLDs when their units do not cross their LD in an assault formation.
  It is usually a linear terrain feature perpendicular to the direction of attack and recognizable under conditions