text: Pursuit
  encircling force and address enemy elements located beyond that forward boundary. The rear boundary
  becomes the boundary between the direct pressure force and the follow and support force.
  7-16. If the encircling force is a ground element, the control measures are almost identical to those used
  during an envelopment, as shown in figure 7-3. Units designate routes, axis of advance, or assigned areas
  adjacent to that of direct pressure forces to allow the encircling force to move parallel to retrograding enemy
  forces and eventually move ahead of those enemy forces. Commanders can designate terrain objectives as
  guides for encircling forces. However, commanders may change these objectives rapidly and frequently,
  based on the progress of encircling forces and enemy actions. These objectives should be terrain features that
  provide encircling forces defensible terrain that enemy forces cannot easily bypass. Units often select choke
  points, such as defiles and bridges, as objectives for the encircling force.
  Figure 7-3. Example pursuit control measures
  7-17. Units establish boundaries or RFLs between the forces conducting the encircling and direct pressure
  forces before those encircling forces reach their objectives. Other FSCMs should relieve encircling forces of
  unnecessary fire support coordination responsibilities. The overall commander directs security operations
  beyond those encircling forces, allowing them to engage retrograding enemy forces without devoting
  resources to flank and rear security. The overall commander establishes additional control measures to control
  the convergence of both elements of the friendly force, such as RFLs, phase lines, and contact points.