text: Command and Support Relationships
  Combination Command Structure
  B-44. In a combination command structure, the lead nation concept and a parallel command structure exist
  simultaneously in a coalition. This occurs when two or more nations are the controlling elements for a mix
  of international forces. This structure is more desirable than the parallel command structure, but an effort to
  achieve a total lead-nation concept for unity of command is preferred.
  NORTH ATLANTIC TREATY ORGANIZATION COMMAND RELATIONSHIPS AND AUTHORITIES
  B-45. NATO is an example of a multinational organization with agreed upon structure and authorities. When
  planning and conducting operations as part of NATO, it is particularly important for leaders to understand
  the command relationships and the specified authorities, whether they are attached to a NATO command or
  receiving NATO capabilities. It is also important to understand that NATO terms and acronyms are similar
  to U.S. acronyms at times, but they often describe different authorities than joint and Army terms. NATO
  has five command relationships:
  (cid:122) Full command (FULLCOM).
  (cid:122) Operational command (OPCOM).
  (cid:122) OPCON.
  (cid:122) Tactical command (TACOM).
  (cid:122) TACON.
  (See table B-5 on page B-12 for a listing of NATO treaty organization command relationships. See Allied
  Tactical Publication 3.2.2 and AJP-3 for additional discussion of the authorities for each command
  relationship.)