Field Service Regulations govern all arms of the Army of the United
States.”

SECTION 2.  THE ARMY OF THE UNITED STATES.

The Army of the United States shall consist of the Regular Army, the Volunteer Army, the Officers’ Reserve Corps, the Enlisted Reserve Corps, the National Guard while in the service of the United States, and such other land forces as are now or may hereafter be authorized by law. (Sec. 1, act of June 3, 1916.)

SECTION 3.  RANK AND PRECEDENCE OF OFFICERS AND NONCOMMISSIONED OFFICERS.

The following are the grades of rank of officers and noncommissioned officers: 

1.  Lieutenant general. 2.  Major general. 3.  Brigadier general. 4.  Colonel. 5.  Lieutenant colonel. 6.  Major. 7.  Captain. 8.  First lieutenant. 9.  Second lieutenant. 10.  Aviator, Signal Corps. 11.  Cadet. 12. (a) Sergeant major, regimental; sergeant major, senior grade, Coast Artillery Corps; (b) quartermaster sergeant, senior grade, Quartermaster Corps; master hospital sergeant, Medical Department; master engineer, senior grade, Corps of Engineers; master electrician, Coast Artillery Corps; master signal electrician; band lender; (c) hospital sergeant, Medical Department; master engineer, junior grade, Corps of Engineers; engineer, Coast Artillery Corps. 13.  Ordnance sergeant; quartermaster sergeant, Quartermaster Corps; supply sergeant, regimental. 14.  Sergeant-major, squadron and battalion; sergeant major, junior grade, Coast Artillery Corps; supply sergeant, battalion, Corps of Engineers. 15. (a) First sergeant; (b) sergeant, first class, Medical Department; sergeant, first class, Quartermaster Corps; sergeant, first class, Corps of Engineers; sergeant, first class, Signal Corps; electrician sergeant, first class, Coast Artillery Corps; electrician sergeant, Artillery Detachment, United States Military Academy; assistant engineer, Coast Artillery Corps; (c) master gunner, Coast Artillery Corps; master gunner, Artillery Detachment, United States Military Academy; band sergeant and assistant leader, United States Military Academy band; assistant band leader; sergeant bugler; electrician sergeant, second class, Coast Artillery Corps; electrician sergeant, second class, Artillery Detachment, United States Military Academy; radio sergeant. 16.  Color sergeant. 17.  Sergeant; supply sergeant, company; mess sergeant; stable sergeant; fireman, Coast Artillery Corps. 18.  Corporal.

In each grade and subgrade date of commission, appointment, or warrant determines the order of precedence. (Paragraph. 9 Army Regulations, 1913.)

SECTION 4.  INSIGNIA OF OFFICERS AND NONCOMMISSIONED OFFICERS.

The insignia of rank appearing on the shoulder straps, shoulder loops, or collar of shirt (when shirt is worn without coat) of officers are as follows: