text: Army Sustainment at Echelon
  2-134. Priority establishment: Units with an organic command relationship have priorities established by the
  organic headquarters. In all other command relationships, the gaining unit establishes priorities.
  2-135. Designation of command or support relationships:
  • Units with an organic, assigned, and attached command relationship may be further attached,
  OPCON, or TACON to another organization by the parent/gaining unit. The parent/gaining unit
  may also impose any support relationship on the unit.
  • Units with an OPCON command relationship may be further OPCON or TACON to another
  organization by the gaining unit. The gaining unit may also impose any support relationship on the
  unit.
  • Units with a TACON command relationship may be further TACON to another organization by the
  gaining unit. The gaining unit may also impose any support relationship on the unit.
  ARMY SUPPORT RELATIONSHIPS
  2-136. Army support relationships are direct support, reinforcing, general support-reinforcing, and general
  support. Army support relationships are not command authorities and are more specific than joint support
  relationships.
  2-137. Direct support is a support relationship requiring a force to support another specific force and
  authorizing it to answer directly to the supported force’s request for assistance (joint doctrine considers direct
  support as a mission rather than a support relationship). A unit assigned a direct support relationship retains
  its command relationship with its parent unit but is positioned by and has priorities of support established by
  the supported unit.
  2-138. Reinforcing support is a support relationship requiring a force to support another supporting unit.
  Only like units can be given a reinforcing mission. A unit assigned a reinforcing support relationship retains
  its command relationship with its parent unit but is positioned by the reinforced unit. A unit that is reinforcing
  has priorities of support established by the reinforced unit first, and then by the parent unit.
  2-139. General support-reinforcing is a support relationship assigned to a unit to support the force as a whole
  and to reinforce another similar-type unit. A unit assigned a general support-reinforcing support relationship
  is positioned and has priorities established by its parent unit and secondly by the reinforced unit.
  2-140. General support is that support which is given to the supported force as a whole and not to any
  particular subdivision thereof. Units assigned a general support relationship are positioned and have priorities
  established by their parent unit.
  2-141. Commanders establish support relationships when subordination of one unit to another is
  inappropriate. Assigning support relationships is one aspect of command and control. Commanders assign a
  support relationship when:
  • The echelon of the supporting unit is the same as or higher than that of the supported unit. For
  example, the supporting unit may be a brigade, and the supported unit may be a battalion. It would
  be inappropriate for the brigade to be subordinated to the battalion; hence, the echelon uses an Army
  support relationship.
  • The supporting unit supports several units simultaneously. The requirement to set support priorities
  to allocate resources to supported units exists.
  2-142. Units that have a command relationship with a unit are not designated a support relationship with the
  same unit. Since a command relationship is established, it provides adequate authority for the gaining unit to
  direct support efforts. Support relationships do not alter ADCON.
  2-143. Army support relationships allow supporting commanders to employ their units’ capabilities to
  achieve results required by supported commanders. Supporting commanders clearly designate support
  relationships to subordinate units in OPORDs. The designation must identify the supported unit, the specific
  support relationship designated, and the duration of the relationship. The duration may be based on time,
  duration of a phase, or based on achieving an objective. This information is included in the “Task
  Organization” paragraph of the OPORD. Supported commanders must also identify supporting units to
  subordinates in the same paragraph. Commanders may place this information in annex A of the order. The