In general, it should have the formation of a main body with advance, rear, and flank guards, though each be represented only by a single man.

611. The distances separating the members of the patrol vary according to the ground. If too close together, they see no more than one man; if too widely separated they are likely to be lost to the control of the leader.

Infantry Drill Regulations, United States Army, 1911 — Part 113

With a patrol of four or five men the distances may vary from 25 to 50 yards; with a larger patrol they may be as great as 100 yards.

Infantry Drill Regulations, United States Army, 1911 — Part 113

At times a column of files, separated by the distances prescribed, is a satisfactory formation.

Infantry Drill Regulations, United States Army, 1911 — Part 113

612. The country must be carefully observed as the patrol advances. In passing over a hill, the country beyond should first be observed by one man; houses, inclosures, etc., should be approached in a similar manner or avoided entirely; woods should generally be reconnoitered in a thin skirmish line.

613. The strength and composition of hostile troops must be observed. If they can not be counted, their strength may be estimated by the length of time a column consumes in passing a given point, or by the area covered if in camp.

Patrol leaders should know, if practicable, the uniforms, guidons, etc., of the enemy, as it will assist in determining the class of troops seen when no other means for doing so are available.

Insignia from the enemy's uniforms, picked up by patrols, often convey valuable information by indicating what troops are in the vicinity.

614. Patrols avoid fighting, except in self-defense or in order to prevent the enemy's patrols from gaining valuable information, or when necessary in order to accomplish their mission. In such cases, a patrol should fight resolutely even though inferior in numbers.

615. Information gained by patrols is generally of no value unless received in time to be of use to the commander. Patrol leaders must therefore send back information of importance as soon as it is gained unless the patrol itself is to return at once.

616. If written, messages should state the place, date, hour, and minute of their dispatch. The information contained in them should be clearly and concisely expressed. They should be signed by the patrol leader.

The authorized message book should be used and the form therein adhered to.