"The Drill Regulations are furnished as a guide. They provide the principles for training and for increasing the probability of success in battle. In the interpretation of the regulations the spirit must be sought. Quibbling over the minutæ of form is indicative of failure to grasp the spirit," (Paragraph 4, Infantry Drill Regulations.)
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.