The following System of Drill Regulations for Infantry, prepared by a board of officers consisting of Lieut. Col. John F. Morrison, Infantry; Capt. Merch B. Stewart, Eighth Infantry; and Capt. Alfred W. Bjornstad, Twenty-eighth Infantry, is approved and is published for the information and government of the Regular Army and the Organized Militia of the United States. With a view to insure uniformity throughout the Army, all infantry drill formations not embraced in this system are prohibited, and those herein prescribed will be strictly observed.
The announcement of the guide, when given in connection with a movement, follows the command of execution for that movement. Exception: 1. As skirmishers, guide right (left or center), 2. MARCH. (C.I.D.R., No. 2.)
17. The turn on the fixed pivot by subdivisions is used in all formations from line into column and the reverse.
The turn on the moving pivot is used by subdivisions of a column in executing changes of direction.
18. Partial changes of direction may be executed:
By interpolating in the preparatory command the word half, as Column half right (left), or Right (left) half turn. A change of direction of 45° is executed.
By the command: INCLINE TO THE RIGHT (LEFT). The guide, or guiding element, moves in the indicated direction and the remainder of the command conforms. This movement effects slight changes of direction.
19. The designations line of
Like the excerpt says, it's pretty much a text for drill formations. It's useful, I suppose, if you want to study the history of US Army training, but otherwise a boring read.