An advanced guard may come under Are at any moment, and to provide against surprise (F.S.R., 64), its leading portions may move in extended order. The duties are given in F.S.R., 68, and apply quite completely to so small a body as a platoon. The platoon should be divided into a vanguard and a main guard. For the vanguard, a common plan is simply to extend a section on either side of the road, but I prefer to divide the section into three patrols, or more if strength permits, who work along in a general line—one to search the road and its immediate vicinity, and one on each side. The nature of the country regulates the breadth of ground the centre patrol can search from the road, and the distance to which the others are sent out on each side. The other sections follow as main guard, not so close as to be at once mixed up with the vanguard if fire is opened on the latter, nor so far as to be unable to support it quickly with fire. The advanced guard is responsible for keeping touch with the main body (the company) (F.S.R., 64 (4)), but the company commander should satisfy himself that this is being done. If view is restricted, the main guard must drop a connecting file to keep connection. This file must march with their beards on their shoulders, to see what the company is doing, and let the commander know, and also to signal to the company, if the platoon has had to halt. If the country is open, the commander should still tell off a file for this duty, who will march with the platoon, but be continually on the look-out to the rear. The platoon commander ought, of course, to keep a watch himself, but may have other things to attend to, and it is well to take precautions against the platoon either getting too far in front or letting the company get too close to it, by marching on while the platoon is investigating some suspicious locality. (_b_) _The Platoon as a Flank Guard._ A platoon may sometimes be used as a flank guard, as when a small convoy is on the march with only a company or two as escort. Flank guards are dismissed in a few words in F.S.R., 70. It is worth while to practise them once or twice to avoid delay in taking up the formation when the march is being started, or in improvising a method of fighting off the enemy if he attacks. Represent the convoy or whatever it is by a man with a red flag to move along the road; the platoon is then to move along parallel to the road, and far enough off to afford protection from effective rifle fire, i.e., at least eight hundred yards in open country. The skeleton enemy should be instructed to keep about the same distance again on the flank beyond the platoon, and to move along parallel with it without closing in, opening fire on an agreed signal.