text: Armies, Corps, and Divisions
  1-92. Inherent in command is the authority that a military commander lawfully exercises over subordinates,
  including the authority to assign missions and accountability for their successful completion. Although
  commanders may delegate authority to accomplish missions, they may not absolve themselves of the
  responsibility for the accomplishment of these missions. Authority is never absolute; the establishing
  authority specifies its extent in accordance to DOD directives and U.S. law. The specific command
  relationship—combatant command, command authority (COCOM), OPCON, tactical control (TACON), and
  support—will define the level of authority each commander has over assigned forces. Of note, joint and Army
  command relationships are not the same. (See Appendix A for a brief summary of the joint command and
  support relationships.)
  1-93. The typical operational chain of command extends from the combatant commander to a JTF
  commander, then to a functional component commander or a Service component commander. JTFs and
  functional component commands, such as the joint force land component, comprise forces normally assigned
  to a Service component command but placed OPCON to a JTF, and subsequently to a functional component
  commander. Conversely, the combatant commander may designate one of the Service component
  commanders as the JTF commander or as a functional component commander. In some cases, the combatant
  commander may not establish a JTF, retaining OPCON over subordinate function commands and Service
  components directly. (See Appendix B for possible joint task force components.)
  1-94. A JTF is the organization most often used by a combatant commander for contingencies. Combatant
  commanders establish JTFs and designate the JFCs for these commands. Those commanders exercise
  OPCON of all U.S. forces through functional component commands, Service components, subordinate JTFs,
  or a combination of these. (See JP 3-33 for a detailed description of combatant commanders).
  1-95. Support is a command authority in joint doctrine. When one organization should aid, protect,
  complement, or sustain another force, a supported and supporting relationship is established by a superior
  commander between subordinate commanders. Designating a support relationship does not provide authority
  to organize and employ commands and forces, nor does it include authoritative direction for administrative
  and logistics support.
  1-96. JP 1 specifies four categories of support:
  * General support.
  * Mutual support.
  * Direct support.
  * Close support.
  1-97. General support is support given to the supported force as a whole and not to any particular subdivision
  thereof. Mutual support is that support that units render each other against an enemy because of their assigned
  tasks, their position relative to each other and to the enemy, and their inherent capabilities. Direct support is
  a mission requiring a force to support another specific force and authorizing it to answer directly to the
  supported force’s request for assistance. Close support is that action of the supporting force against targets
  or objectives sufficiently near the supported force as to require detailed integration or coordination of the
  supporting action with the fire, movement, or other actions of the supported force.
  1-98. Joint support relationships are somewhat vague but very flexible. Establishing authorities ensure both
  supported and supporting commanders understand the authority of supported commanders. JFCs often
  establish supported and supporting relationships among components. For example, the maritime component
  commander is normally the supported commander for sea control operations; the air component commander
  is normally the supported commander for counterair operations. Another example, a field army headquarters
  designated as the joint force land component may be the supporting force during some campaign phases and
  the supported force in other phases. Often the JFC specifies only a supported and supporting relationship
  between forces. In that case, the supporting force will be in general support.
  Note. A joint support relationship is not used when an Army commander task-organizes
  subordinate Army forces. When task-organized to support another Army force, Army forces use
  one of four Army support relationships: direct support, reinforcing, general support, or general
  support - reinforcing. (See ADP 3-0 for more information on Army support relationships.)