text: Chapter 6
  Figure 6-7. Infiltration lane
  PENETRATION
  6-110. Apenetrationis a form of maneuver in which an attacking force seeks to rupture enemy defenses
  on a narrow front to disrupt the defensive system (FM 3-90-1). Destroying the continuity of the enemy’s
  defense causes the enemy’s isolation and defeat in detail. The penetration extends from the enemy’s security
  zone through the main defensive positions and the rear area. A commander executes a penetration when time
  pressures do not permit an envelopment,there is no assailable flank,enemy defenses are overextended,and
  weak spots are detected in the enemy’s positions through reconnaissance, surveillance, and security
  operations.
  6-111. Penetrating a well-organizedposition requires massing overwhelming combat powerat the point of
  penetration and combat superiority to continue the momentum of the attack. The BCT commander designates
  a breach force,support force,assault force,and a reserve. The commander can designate these elements for
  each defensive position that requires penetration. The commander assigns additional units follow and support
  or follow-and-assume missions to ensure rapid exploitation of initial success. The commander designates
  forces to fix enemy reserves in their current locations and isolate enemy forces within the area selectedfor
  penetration. (See figure 6-8.)