Active Unit. A major command (MAJCOM), field operating agency (FOA), or direct reporting unit (DRU) constituted and activated by Headquarters US Air Force (HQ USAF); or a subordinate unit constituted by HQ USAF, assigned to a MAJCOM, FOA, or DRU and activated by special order.

Inactive Unit. A unit constituted by Headquarters US Air Force but not yet activated or a unit constituted, activated, and subsequently, inactivated.

Disbanded Unit. A unit whose legal authority for existence is withdrawn by Headquarters US Air Force. Its designation is retired and preserved in historical records.

Parent Unit. An organization that directly administers units, detachments, or operating locations assigned to it.

Provisional Unit. A temporary unit organized to perform a specific task.

Attached Unit. A unit, or part of a unit, placed under the control of another organization for a specific purpose such as operational control, administrative control, or logistic support. It is still assigned to the parent unit.

Detached Unit. A unit serving away from its organization of assignment. It may function independently, or may be attached to another organization.

Primary Subordinate Unit. A unit that performs part or all of the primary mission of the organization to which it is assigned. The unit reports to the commander of the parent organization and has full authority to execute its assigned mission.