text: _________________________________________________________________________________Chapter 4
  A particular unit’s position on a subsequent line may not be directly behind
  its previous position. In the spaces between the lines, the defenders can or-
  ganize reconnaissance fire, raids, and counterattacks. Thus, it is difficult for
  the enemy to predict where he will encounter resistance.
  4-97. The number of lines and duration of defense on each line depend on the
  nature of the enemy’s actions, the terrain, and the condition of the defending
  units. Lines are selected based on the availability of natural obstacles and
  shielding terrain, with consideration of being able to leave the lines without
  being observed.
  OSC
  Support Zone Shielding Force Battle Zone Contact Force Disruption Zone
  City X
  X
  XX
  KILL
  X Marsh ZONE
  KILL
  Attack Zone ZONE
  XX
  KILL
  X ZONE
  C
  X X
  X
  KILL
  ZONE C
  X
  City
  Attack Zone
  X XX
  KILL
  X ZONE
  Mountains
  LEGEND
  C Cover Shielding Contact
  Force Force
  OSC
  Figure 4-5. Maneuver Defense (Example 2)
  Defensive Maneuver
  4-98. Defensive maneuver consists of movement by bounds and the mainte-
  nance of continuous fires on enemy forces. A disruption force and/or a main
  defense force (or part of it) can perform defensive maneuver. In either case,
  the force must divide its combat power into two smaller components: a con-
  tact force and a shielding force. The contact force is the component occupying
  the forward-most defensive line at any point in time. The shielding force is
  the component occupying the next line immediately to the rear.