TRAINING.--In formulating any scheme for the exercise of troops in Advanced Guard work all officers and other ranks should be made to understand the nature of the scheme, and should be informed (a) whether the force is advancing or retreating, whether it is moving before or after action with the enemy, and whether it is in a friendly or a hostile country; (b) what is known of the enemy; (c) the direction and objective of the march; (d) the general intentions of the commander of the Main Body; and (e) the general instructions issued to the commander of the Advanced Guard. "Unless such exercises are carried out in a practical manner, young officers and inexperienced N.C.O.'s will get the impression that an Advanced Guard consists merely of a procession of small bodies of infantry, strung out at fixed intervals on a single road. It is of the highest importance that the training should be carried out on the lines that would be adopted in action" (G.H.Q. Circular). TACTICAL PRINCIPLES.--"Speed of advance is the first consideration when not in contact with the enemy. Hence an Advanced Guard will move on a narrow front along roads and other channels of communication, with such distances between advanced and supporting bodies as to avoid possibility of surprise. When in contact with, or in the vicinity of, the enemy, security and speed of advance are equal considerations. Hence the Advanced Guard should move by bounds on a broad fighting front across country" ("Infantry Training, 1921").