With the advance cavalry in front but little reconnoitering by infantry is necessary, and the advance party is relatively small--one eighth to one third of the support. If there is no advance cavalry, the advance party is made stronger (about one half of the support) and the flanks are guarded, if necessary, by additional patrols sent out from the support and even from the reserve. The support commander ordinarily marches with the advance party, but goes wherever needed. He sees that the proper road is followed; that guides are left in towns and at crossroads; that necessary repairs are made to roads, bridges, etc., and that information of the enemy or affecting the march is promptly transmitted to the advance-guard commander. He endeavors promptly to verify information of the enemy. RESERVE The reserve follows the support at several hundred yards' distance. It consists of the remainder of the infantry and engineers, the artillery, and the ambulance company. The artillery usually marches near the head of the reserve, the engineers (with bridge train, if any) and special troops at the rear. RECONNAISSANCE In conducting the reconnaissance the patrols are, as a rule, small--from two to six men. If additional protection is necessary, a flank guard covers the threatened flank. The flanking patrols, whether of the advance cavalry or advance party, are sent out to examine the country wherever the enemy might be concealed. If the nature of the terrain permits, these patrols march across country or along roads and trails paralleling the march of the column. For cavalry patrols this is often possible; but with infantry patrols and even with those that are mounted, reconnaissance is generally best done by sending the patrols to high places along the line of march to overlook the country and examine the danger points. These patrols report or signal the results of their observations and, unless they have other instructions, join their units by the most practicable routes, other patrols being sent out as the march proceeds and as the nature of the country required. Deserters, suspicious characters, and bearers of flags of truce, the latter blindfolded, are taken to the advance-guard commander. Civilians are not permitted to precede the advance guard. Communication between the fractions of an advance guard and between the advance guard and main body is maintained by wire, messenger service, or signals. ADVANCE GUARD OF A SMALL COMMAND In forming the advance guard of a command smaller than a brigade, the foregoing distribution is modified, depending upon the situation. A company or troop usually sends forward only a point, a battalion or squadron, an advance party; but a battalion or squadron at war strength should put a company or troop in the advance guard and a regiment should put a battalion or squadron, if an enemy is liable to be met. Whenever the advance guard is less than a battalion, there is no reserve. REAR GUARDS