Center: The middle point or element of a command.
Column: A formation in which the elements are placed one behind another.
Deploy: To extend the front. In general to change from column to line, or from close order to extended order.
Depth: The space from head to rear of any formation, including the leading and rear elements. The depth of a man is assumed to be 12 inches.
Distance: Space between elements in the direction of depth. Distance is measured from the bark of the man in front to the breast of the man in rear. The distance between ranks is 40 inches in both line and column.
Element: A file, squad, platoon, company, or larger body, forming part of a still larger body.
File: Two men, the front-rank man and the corresponding man of the rear rank. The front-rank man is the file leader. A file which has no rear-rank man is a blank file. The term file applies also to a single man in a single-rank formation.
File closers: Such officers and noncommissioned officers of a company as are posted in rear of the line. For convenience, all men posted in the line of file closers.
Flank: The right or left of a command in line or in column: also the element on the right or left of the line.
Formation: Arrangement of the elements of a command. The placing of all fractions in their order in line, in column, or for battle.