Topic: AIF - Lighthorse
The Australian Light Horse,
Militia and AIF
Military Board, Light Horse Manual for the Drill Training and Exercise of the Light Horse Regiments of Australia, 1st January 1910, (Melbourne 1909), pp. 131 - 3.
S. 212. GROUND SCOUTS.
 Although every man in the squadron is to be instructed in the duties of ground scouts, a sufficient number of men must be selected for their superior intelligence and good horsemanship, and especially trained as the scouts of the squadron. The duties of scouts are to ascertain whether the ground in the immediate vicinity, in front of the squadron (and on its flanks in column), is suitable for mounted troops, to point out obstacles, and to indicate the best points of passage. Scouts must be careful not to unnecessarily expose themselves to view on high ground, or against the sky line.
Single troops should always throw out scouts in difficult ground; a squadron should never manoeuvre over unknown or broken ground without being preceded by a ground scout. The number of scouts employed, and the distance to which they are to go out, must depend upon the nature of the ground and the rapidity with which the body is moving ; they must not,  however, be more numerous than is absolutely necessary, and must be sufficiently in advance to give ample warning of obstacles, but never out of sight of their squadrons.
Under ordinary circumstances, one man per squadron is sufficient, and, as a general rule, ground scouts should not be less than 200, nor more than 500 yards at the outside, away from their squadrons; if on a flank, they must know what sort of ground intervenes between them- and the column.
Squadron commanders are responsible (without any order) that one scout from each squadron gallops out to a point at a suitable distance, as explained above, in front of the centre of his squadron if in line, or line of squadron columns, or opposite the exposed flank of the squadron; in the latter case, also, the leading squadron sends out an additional scout ahead of the column. After reaching this point, each scout conforms as far as possible to the pace and to any change of direction of his squadron.
When moving fast over very difficult ground, two scouts may with advantage be sent out by each squadron; one man can then halt to point out a passage, while the other explores the nature of the ground.
The following signals are to be used by ground scouts:-If the ground is boggy, or otherwise impassable, they will halt and raise their rifles perpendicularly; they will then make for what ever point appears practicable, pointing towards it with the rifle.
If the ground within view in front and on either side is quite impracticable, a scout will face his squadron, raise his rifle and ride in to the squadron to report,  As the duties of ground scouts in broken ground take a good deal out of the horses, squadron commanders will be careful to equalize the work among their scouts, and to save all unnecessary galloping; thus, if a line retires over ground not previously traversed, fresh scouts will be sent out to the new front, and those already out will rejoin their squadron.
Citation: The Australian Light Horse, Militia and AIF, Regimental Scouts