Ranks and Ratings
There are three types of officer - commissioned officers, warrent officers, and noncommissioned officers.
Commissioned officers are those from full general down to second lieutenant, who have been commissioned by the President, acting as Commander-in-Chief of the Army. Male officers are addressed as "Sir," Wac officers as "Ma'am."
Warrent officers, senior and junior grade, hold warrants of their rank issued by the Secretary of War. They rank between commissioned officers and noncommissioned officers. They rate salutes. Make warrant officers are addressed as "Mister," and Wac warrant officers as "Miss."
Noncommissioned officers, from master sergeants to corporals, are appointed by their supperiors when they have proved themselves worthy. They do not rate salutes.
Privates, first class, are not considered noncommissioned officers, although promotions to this rank are awarded as in the cases of the latter.
From the Ordinance Soldiers Guide
CHAIN OF COMMAND extends from the corpora lwho