text: Linkup
  TYPES OF LINKUPS
  20-27. The linkup force concentrates its efforts on completing the linkup. Linkup operations frequently will
  require a passage of lines. Regardless of the purpose of the linkup, the operation will take on one of two
  forms:
  * Linkup of a moving force with a stationary force.
  * Linkup of two moving forces.
  LINKUP OF A MOVING FORCE WITH A STATIONARY FORCE
  20-28. To ensure the forces join without engaging one another, linkup points are at locations where the axis
  of advance of the linkup force intersects the security elements of the stationary force. (See figure 20-1.) These
  points must be readily recognizable to both forces. Units plan alternate points in the event enemy activities
  cause linkup at places other than those planned. The number of linkup points selected depends on the terrain
  and number of routes used by the linkup force. Personnel in the linkup force must be thoroughly familiar
  with mutual identification procedures and plans for rapid passage of lines. Stationary forces assist in the
  linkup by opening lanes in minefields, breaching or removing selected obstacles, furnishing guides, and
  designating avenues of approach. Use of a common radio frequency enhances coordination and
  responsiveness between forces.
  Figure 20-1. Linkup of a moving force with a stationary force
  LINKUP OF TWO MOVING FORCES
  20-29. Linkup between two moving forces is one of the most difficult operations often conducted to
  complete the encirclement of an enemy force. Units plan primary and alternate linkup points for two moving
  forces on boundaries where the two forces are expected to converge. As linking forces move closer, positive
  control must be coordinated to ensure they avoid firing on one another. This deliberate coordination ensures