Military Titles and Organizations

The proper nouns for the armed forces (and their branches and units) are capitalized, as are short forms referring to specific organizations. The terms 'army', 'navy', etc. are lowercased when standing alone or used collectively and not part of a proper noun. Military titles of rank are capitalized when they are part of a formal title or are used in reference to a specific person. Military titles of rank may be abbreviated when given with the full name of a person and are punctuated and written with initial letters capitalized. Abbreviations for military branches and units are capitalized and unpunctuated. Military medals and awards are capitalized, e.g. Purple Heart. Titles of wars are capitalized.

Examples (with abbreviations, if any):

adjutant general, adjutants general (Adj. Gen. or AG)
admiral (Adm. or Adml. or ADM)
air marshal (AM)
airman (Amn. or AN)
airman basic (AB)
airman first class (A1c. or A/1C)
brevet (Bvt. or Bt.)
brigadier general (Brig. Gen. or B.Gen. or BG)
captain (Capt. or Cpt. or CPT)
captain general (CG)
chief petty officer (CPO)
chief warrant officer (CWO)
colonel (Col. or COL)
command sergeant major (CSM or Command Sgt. Maj.)
commander (Cmdr. or Comdr. or Cdr. or CDR)
commander in chief, commanders in chief
commanding general (CG)
commanding officer (CO)
corporal (Cpl.)
ensign (Ens. or ENS)
first lieutenant (1st Lt.)
first sergeant (1st Sgt.)
fleet admiral (FADM)
flight lieutenant (FL)
general (Gen.)
general of the armies
generalissimo, generalissimos
gunnery sergeant (Gy. Sgt. or Gunnery Sgt.)
inspector general, inspectors general (Insp. Gen.)
lance corporal (LC or LCpl or Lance Cpl.)
lieutenant (Lt. or Lieut.)
lieutenant colonel (Lt. Col. or LTC)
lieutenant commander (Lt. Cmdr. or Lt. Comdr. or LCDR)
lieutenant general (Lt. Gen. or LTG)
lieutenant, junior grade (Lt.(jg) or LTJG or Lt. j.g.)
major (Maj.)
major general (Maj. Gen. or MG)
master chief petty officer (CPOM or MCPO)
master gunnery sergeant (M. Gy. Sgt. or Master Gunnery Sgt.)
master sergeant (M. Sgt. or MSG or Master Sgt.)
petty officer (PO)
petty officer first class
petty officer second class
petty officer third class
platoon sergeant (Platoon Sgt.)
private (Pvt. or Pte.)
private 1 (Pvt. 1)
private 2 (Pvt. 2)
private first class (Pfc. or PFC)
rear admiral (Rear Adm. or R.Adm. or RA or RADM)
rear admiral lower half (Rear Adm.)
rear admiral upper half (Rear Adm.)
seaman (Sea.)
seaman apprentice (SA)
seaman first class (S1c.)
seaman recruit (SR)
second lieutenant (2d Lt.)
senior airman
senior chief petty officer (CPOS or SCPO)
senior master sergeant (S. M. Sgt. or Senior Master Sgt.)
senior naval officer (SNO)
sergeant (Sgt. or Serg. or Sergt. or SG)
sergeant at arms, sergeants at arms
sergeant first class (Sfc. or SFC)
sergeant first class (Sgt. 1st Class)
sergeant major of the Army (SMA or Army Sgt. Maj.)
sergeant major, sergeants major or sergeant majors (Sgt. Maj. or S.Maj. or SM)
specialist (Spc.)
specialist third class (Sp3c.)
staff sergeant (Staff Sgt.)
staff sergeant major (Staff Sgt. Maj.)
surgeon general, surgeons general (Surg. Gen. or SG)
technical sergeant (T. Sgt. or Tech. Sgt.)
technician second grade (T2g.)
vice admiral (Vice Adm. or V.Adm. or VA or VADM)
warrant officer (WO)
warrant officer junior grade (WOJG)