text: Chapter 4
  EARLY ENTRY COMMAND POST
  4-36. The early-entry command post is a lead element of a headquarters designed to control operations until
  the remaining portions of the headquarters are deployed and operational (FM 6-0). The early-entry command
  post is an ad hoc organization of equipment and personnel from the staffs of the tactical, main, and rear
  command posts. The tactical command post usually provides the base for the early-entry command post. The
  corps adds or subtracts personnel based on mission requirements. The early-entry command post includes a
  mix of current operations personnel, planners, and sustainers able to coordinate the reception of the corps
  and plan its initial operations. It is usually led by the corps deputy commanding general.
  4-37. The corps early-entry command post is established to maintain forward situational awareness early in
  any corps deployment. It facilitates the deployment and onward movement of the corps and its assigned
  forces, coordinates with outside military and other government organizations as required, and provides
  limited command and control of assigned or attached forces when required. Ideally, manning and equipment
  should allow the early-entry command post to deploy aboard a single aircraft, although the composition
  adjusts to the lift available. In a non- or semi-permissive area, security for the early-entry command post
  typically comes from co-location with an already deployed subordinate unit’s command post. If the
  environment is permissive, the early-entry command post may deploy to a host-nation military facility.
  MOBILE COMMAND GROUP
  4-38. The mobile command group consists of specially equipped vehicles that allow the corps commander
  to move by ground in the land portions of the JOA and have network access to the common operational
  picture, subordinate commanders, and the corps staff. In addition to the drivers and gunners, the commander
  normally selects a small number of staff experts to handle en route communications and coordination. The
  mission and the commander’s preference dictate the composition. When distance or circumstances require
  air movement, a supporting aviation brigade has specially equipped command and control helicopters that
  can substitute for ground vehicles.
  4-39. The mobile command group is not capable of exercising command and control to the same degree as
  the three command posts. Its primary purpose is to assist the commander with maintaining the necessary
  situational awareness to make critical decisions while moving between command posts or subordinate units
  during the conduct of operations.
  SUBORDINATE FORMATIONS
  4-40. The capabilities of a corps are tailored for each mission by adjusting the corps’ composition. Usually,
  a corps commands between two to five divisions, a mix of functional and multifunctional brigades, additional
  BCTs, and a variety of smaller enabler units. The smaller enablers usually come from higher echelon assets
  and augment the corps’ capabilities.
  ASSIGNED FORCES
  4-41. The corps routinely has units that are attached or assigned to it. This includes two to five divisions,
  additional BCTs, an ESC, a MEB, an expeditionary military intelligence brigade, a field artillery brigade, an
  engineer brigade, a military police brigade, a corps signal brigade, and a medical brigade. Based on the
  assigned tasks of the divisions and the allocation of brigades, the corps commander determines the
  appropriate command and support relationships for subordinate divisions and brigades. A corps may retain
  some forces to consolidate gains concurrently with other operations.
  4-42. The corps routinely controls multinational forces in accordance with their individual national caveats.
  The organization of these units varies as will their support and sustainment capabilities. The corps
  commander should give particular attention to the national capabilities and limitations of each multinational
  partner. Some limitations are tactical, while others may be political. Normally, a corps receives a digital
  liaison detachment to support multinational interoperability (see paragraph 3-89 for more on digital liaison
  detachments). Figure 4-1 provides an example of the corps and available enablers.