Troop officers may use this method of instructing noncommissioned officers in patrolling, advance and rear guard duty, outposts, and in squad leading, in writing messages, in selecting positions for trenches, and in constructing and concealing same. This form of instruction is called "a tactical ride or, if dismounted, a tactical walk." It is very greatly used by all foreign armies. Exercises along the same general lines are conducted for field and staff officers and even general officers, and are called "tactical rides" and "strategical rides," depending upon their object. After some proficiency has been attained as a result of these tactical rides, the greatest interest and enthusiasm can be awakened in this work by sending out two patrols the same day, one to operate against the other. Each should wear a distinctive uniform. The strength of each patrol, its starting point, route to be followed, and its orders should all be unknown to the other patrol. If blank ammunition is used, an officer should supervise its issue and carefully inspect to see that no man carries any ball cartridges. One umpire should accompany the commander of each party. Each umpire should be fully informed of the strength, orders, and route of both patrols. He must, however, carefully avoid giving suggestions or offering any information to the commander. Observers in these small maneuver problems are generally in the way and none should be permitted to be along. These small maneuvers may be gradually developed by having one side establish an outpost or fight a delaying action, etc. It should always be remembered that there is no hard and fast rule prescribing how a patrol of three, five, or any number of men should march. The same is equally true of advance guards, and applies also to the establishment of outposts. It is simply a question of common sense based on military knowledge. Don't try to remember any diagrams in a book. Think only of what you have been ordered to do and how best you can handle your men to accomplish your mission, and at the same time save the men and horses from any unnecessary hardships. Never use two or more men to do what one can do just as well, and don't let your men get beyond your control. In addition to the signals prescribed in the Cavalry Drill Regulations, the following should be clearly understood by the members of a patrol: Enemy in sight in small numbers, hold rifle above the head horizontally; enemy in force, same proceeding, raising and lowering the rifle several times; take cover, a downward motion of the hand. Other signals may be agreed upon, but they must be familiar to the men; complicated signals are avoided. Signals must be used cautiously so as not to convey information to the enemy. =Section 4. Advance guards.=