Machine guns are especially useful in the passage of defiles and in covering the crossings of rivers.
Engineers and ambulance companies are usually assigned to rear guards.
The troops of a rear guard are selected from those that have had previous local successes, or have suffered little loss and are comparatively fresh.
DISTRIBUTION OF TROOPS
The proximity and conduct of the enemy control, to a large extent, the formation of a rear guard. When it is not necessary to withdraw in deployed lines, the greater part of the rear guard marches on the road in column of route, taking up a formation resembling that of an advanced guard faced to the rear. The distribution of troops is therefore similar to that of an advance guard, namely:
/P Reserve. Support. Rear cavalry. P/
The rear cavalry is that portion of the rear-guard cavalry following the support. The support, as in an advance guard, is divided into two parts; that part nearest the enemy is called the rear party and marches with a rear point.
DISTANCES
The distance of the rear guard from the main body and between the fractions of the rear guard are about the same as in the case of an advance guard. If marching at night, the rear guard draws nearer the main body.