[33]. 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.
[34]. 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.
[35]. Flank: The right or left of a command in line or in column; also the element on the right or left of the line. (See [Figs. 2], [3] and [4].)
[36]. Formation: Arrangement of the elements of a command. The placing of all fractions in their order in line, in column, or for battle.
[37]. Front: The space, in width, occupied by an element, either in line or in column. The front of a man is assumed to be 22 inches. Front also denotes the direction of the enemy. (See [Figs. 2], [3] and [5]).
[38]. Guide: An officer, noncommissioned officer, or private upon whom the command or elements thereof regulates its march.
[39]. Head: The leading element of a column. (See [Figs. 4], [5] and [6].)
[40]. Interval: Space between elements of the same line. The interval between men in ranks is 4 inches and is measured from elbow to elbow. Between companies, squads, etc., it is measured from the left elbow of the left man or guide of the group on the right, to the right elbow of the right man or guide of the group on the left. (See [Fig. 3].)
[41]. Left: The left extremity or element of a body of troops.
[42]. Line: A formation in which the different elements are abreast of each other. (See [Figs. 2] and [3].)