text: Appendix B
  Command and Support Relationship
  This appendix is derived from FM 3-0. It discusses command and support relationships
  for joint and Army forces. This appendix delineates the four types of joint command
  relationships, Army command relationships, and Army command support
  relationships. Command and support relationships provide the basis for unity of
  command and unity of effort in operations.
  FUNDAMENTAL CONSIDERATIONS
  B-1. Establishing clear command and support relationships is a key aspect of any operation. Large-scale
  combat operations present unique and complex challenges that demand well-defined command and support
  relationships among units. These relationships establish responsibilities and authorities between subordinate
  and supporting units. Some command and support relationships limit the commander's authority to prescribe
  additional relationships. Knowing the inherent responsibilities of each command and support relationship
  allows commanders to effectively organize their forces and helps supporting commanders understand their
  unit's role in the organizational structure.
  JOINT COMMAND RELATIONSHIPS
  B-2. As part of a joint force, Army commanders and staffs must understand joint command relationships.
  JP 1 specifies and details four types of joint command relationships:
  * Combatant command (command authority).
  * Operational control (OPCON).
  * Tactical control (TACON).
  * Support.
  COMBATANT COMMAND (COMMAND AUTHORITY)
  B-3. Combatant command is a unified or specified command with a broad continuing mission under a single
  commander established and so designated by the President, through the Secretary of Defense and with the
  advice and assistance of the Chairman of the Joint Chiefs of Staff (JP 1). Title 10, United States Code, section
  164 specifies this authority in law. Normally, the CCDR exercises this authority through subordinate JFCs,
  Service component commanders, and functional component commanders.
  OPERATIONAL CONTROL
  B-4. Operational control is the authority to perform those functions of command over subordinate forces
  involving organizing and employing commands and forces, assigning tasks, designating objectives, and
  giving authoritative direction necessary to accomplish the mission (JP 1). Operational control normally
  includes authority over all aspects of operations and joint training necessary to accomplish missions. It does
  not include directive authority for logistics or matters of administration, discipline, internal organization, or
  unit training. The CCDR must specifically delegate these elements of COCOM. Operational control does
  include the authority to delineate functional responsibilities and operational areas of subordinate JFCs. In
  two instances, the Secretary of Defense may specify adjustments to accommodate authorities beyond
  OPCON in an establishing directive- when transferring forces between CCDRs or when transferring
  members or organizations from the military departments to a combatant command. Adjustments will be
  coordinated with the participating CCDRs.