AR 220-5 governs general policies and rules for the designation, classification, and change in status of Army units.
View AR 220-5 on armypubs.army.mil
It distinguishes modification table of organization and equipment units from table of distribution and allowances units. It addresses significant status changes, approving authorities, orders, reporting, records, and coordination requirements.
Applies to: The actions listed in table 21 are significant changes in the status of units of the Regular Army, USAR, and ARNG while in Federal service.
Any action that changes the organizational structure, designation, assignment, or location of a military unit is a change in the status of that unit. (paragraph 2-2)
Unit status changes are made a matter of record for legal and historical purposes. (paragraph 2-2)
CMH records constitutions, activations, inactivations, designations, redesignations, consolidations, reorganizations, assignments, permanent changes of station, and similar actions concerning the unit and its organic elements. (paragraph 2-2)
All orders announcing significant changes must include CMH (ATMHHPO) in distribution. (paragraph 2-2)
The effective date is the date specified in the orders or the date of the orders if no effective date is specified. (paragraph 2-2)