text: Chapter 5
  Generally, engineers use rapidly emplaced obstacle systems, which meet the commander’s intent during
  screening operations. Situational obstacles disrupt and delay the threat, in conjunction with fires, to protect
  elements of the screening unit and main body.
  COMMAND AND CONTROL AND SUSTAINMENT
  5-48. Commanders position themselves and their command posts to support command and control forces
  over extended distances and to maintain communications and digital linkages with higher headquarters and
  subordinate elements. Initial and subsequent locations of the command posts integrate into the BCT
  communications plan to ensure continuous digital connectivity. BCT and squadron commanders place
  themselves in positions that maximize their ability to command their units and gain situational awareness.
  5-49. Prepare sustainment assets for operations in both time and space. Units screening forward or to the
  flanks of the BCT may require support from the closest battalion. Priorities and sources of support are
  determined early in the planning process to allow the supporting sustainment unit time to conduct planning,
  coordinate with adjacent units, and position assets to provide sustainment to the screening units.
  5-50. The screen’s scheme of maneuver, engagement, and disengagement criteria nested within the BCT
  plan defines the conditions or time criteria triggering transition. PLs and checkpoints control transition.
  Transition of a screening unit is a decision point that marks a shift from security operations to offensive or
  defensive operations.
  Note. As stated earlier in chapter 4, the BCT or squadron commander may establish additional
  routes as a control measure to conduct transitions while maintaining freedom of maneuver and
  controlling maneuver forces without slowing or congestion of one single route (see
  paragraph 4-70, page 4-16).
  MOVING SCREEN (FLANK AND REAR)
  5-51. A squadron or screening unit executes a moving screen by implementing movement techniques. The
  screen movement relies upon time and distance factors associated with the BCT’s movement.
  Responsibilities for a moving flank screen begin at the front of the BCT’s lead combat element, and ends at
  the rear of the protected force excluding front and rear security forces. The screening unit, typically the
  Cavalry squadron, may conduct moving flank screens or screen the rear of the BCT.
  5-52. As with a stationary screen, PLs, checkpoints, contact points, and lateral boundaries aid to orient and
  control the screening unit’s movement. The LD, which is the same for the protected force, initiates the screen
  mission and becomes the rear boundary of the moving screen.
  5-53. The planning considerations discussed earlier for stationary screens apply to a moving screen.
  However, emphasis may shift because the BCT is moving. As the BCT force moves, the screening unit
  occupies a series of successive screens, regulating movement to maintain the time and distance factors the
  main body commander desires. As with the stationary screen, integrating attack and reconnaissance aviation
  units and UASs into the screen affords increased flexibility, fires platforms, and sensors to the mission.
  Note. Cavalry units do not conduct a moving screen to the front of a stationary force or a stationary
  screen in front of a moving force. They could conduct an advance guard, reconnaissance in force,
  or zone reconnaissance to the front of a moving force.
  GUARD
  5-54. Guard is a type of security operation done to protect the main body by fighting to gain time while
  preventing enemy ground observation of and direct fire against the main body (ADP 3-90). Units conducting
  a guard cannot operate independently because they rely upon fires and functional and multifunctional support
  assets of the main body. A commander assigns a guard operation when the BCT expects contact or has an
  exposed flank that requires greater protection than a screen can provide. The guard force conducts
  reconnaissance, attacks, defends, delays, and screens as needed to provide reaction time and maneuver space