text: Security Operations
  Movement During Moving Flank Security Missions
  13-45. There are three techniques of occupying and moving in a flank security area for moving security
  missions. These techniques are based on how the security force crosses the LD:
  * Separately from the main body and deploys to perform the mission.
  * Separately from main body, lead elements conduct a movement to contact.
  * With the main body and conducts a zone reconnaissance out to the limit of the security area.
  13-46. Commanders should not require the security force to make its own penetration when it faces prepared
  enemy defenses. This may prevent or significantly delay the security force from assuming its duties. They
  often combine the three techniques described in paragraphs 13-47 through 13-49.
  Separately from the Main Body and Deploys to Perform the Mission
  13-47. In the first technique, the security force crosses the LD separately from the main body and deploys
  to execute the mission. The security force then conducts a tactical movement parallel to the main body and
  drops off observation posts or occupies BPs along the flank of the main body. This technique keeps the two
  forces from interfering with each other during deployment. When another force penetrates the line of contact
  and the main body is not in contact with the enemy force and moves quickly, it is appropriate that the LD is
  uncontested, and outputs from the IPB process indicate unlikely enemy contact. It is the fastest but least
  secure technique. Figure 13-1 depicts this technique.
  Figure 13-1. Example of the security force crossing LD separately to deploy and establish a
  flank screen
  Separately from the Main Body and Lead Elements Conduct a Movement to Contact
  13-48. Figure 13-2 on page 13-10 illustrates a second technique. The security force crosses the LD
  separately from the main body, and its lead elements conduct a movement to contact. Follow-on elements
  occupy positions as they reach them. This technique is appropriate when the main body is moving slower