The men should also be practiced in the same way, as the combat patrol or covering detachment of a defensive line. This work is simpler, the patrol generally does not move from position to position. Its mission is the same as in the attack and even more important. In the defense very much depends on the selecting of the best position for this patrol and the correct dispositions being taken. The case must be also considered of a patrol sent out by the defense for reconnaissance or screening which in case of attack becomes the combat patrol. In a battle line with intervals, as in the case of the enveloping attack, connecting files must be used. Their object is to keep the commanders of the subdivision informed as to how the other is progressing. This can generally be done by forming points in the line joining the two inner flanks. In some cases this will not serve. Rules for this can not be given. [Sidenote: Advance guard training] Advance Guard. In most commands too much of our limited field training period is devoted to work of advance and rear guards. It is important and must be taught, but if the other work which is the real foundation for this is properly done but little more time is required outside of the maneuver exercises for training the enlisted men. Patrolling and combat form most of the work in these exercises so far as the men are concerned. There are many tactical problems that come to the officers in this class of work and they must know how to solve them. This is the work of the school for officers and should be effectively done. [Sidenote: Advance guard rencontre] The point is but a patrol with a special mission. The flanking groups are reconnoitering and scouting patrols but they involve some new features. When a rencontre engagement occurs on the march one of the first things the commander wants to know is the strength of the enemy and his location; if deployed, where is his line? Where its flank? If not deployed, what is he doing? As the advance party deploys and pushes on, these flanking groups have the best opportunity to observe and by reconnaissance to gain valuable information. They also become, temporarily at least, combat patrols to the firing line. The men must be taught to carry out this mission without further orders and to do it correctly. In case small detachments attempt to delay our march, these patrols by flanking them can greatly hurry their retreat and prevent the delay of our column. [Sidenote: Maneuver work] The general principle of advance and rear guards should be taught the company. This work can be done in part at the relief map and sand table, but the company should be exercised on the ground as the advance guard of a battalion and as the advance party of a larger advance guard, the other troops being imaginary. Afterwards two companies should work against each other, one as rear party of a rear guard, the other as advance party of an advance guard; also each as advance party in a rencontre.