From Essentials of Infantry Training - Eighth Edition, August, 1940
General. To operate effectively near the enemy, the soldier must be able to conceal himself while halted and moving. If he is able to move, observe and fire without being discovered, not only has he an excellent chance of avoiding being hit, but will be the equal of many of the enemy who lack this ability. Ordinarily individuals who make up the various formations on the battlefield are relatively widely separated, permitting individual initiative in the use of cover and concealment and selection of firing positions. The better trained the individuals, the more widely separated they may be in formation, thus reducing the number of casualties and increasing the effectiveness of the unit. Even expert shots are prone at times to become excited and shoot too wildly when under fire. So shooting from a concealed position is far more effective than from one exposed to fire. The effective use of concealment is of extreme value not only to the soldier but to his unit as well.
Concealment by Day. Following are a few simple rules generally applicable when halted close to the enemy: When not observing, keep as close to the ground as possible. Remain motionless until movement is necessary. Whenever possible observe from the prone position. Keep off the saline. Avoid isolated and conspicuous bushes which attract the enemy's fire.
Movements by Day. a. The soldier close to the
enemy always moves as though he were being observed.
b. When he must move individually from one position to another, he
first studies the ground between his halted location and the desired destination
He looks for a covered route, one concealed by ditches, ravines or woods,
and determines which route should be used. He next looks for any open spaces
which must be crossed and tries to find any intermediate cover, such as folds
in the ground, which will afford him temporary concealment. He determines
his route, at least to the next point of concealment before leaving his halted
position.
c. In moving by covered routes, he advances with caution, with his weapons ready for use. In crossing open ground, he bounds rapidly from cover to cover, throwing himself prone upon reaching each intermediate concealed point.
d. The methods of movement are simple and few. They
should be second nature to the infantryman.
(1) Prone position. The body is flat, the side of the face on the ground,
the legs extended and apart with heels down (turned m) The arms are flat on
the ground. The rifle is usually grasped in the right hand.
(2) To advance by running.
(3) To drop to prone position.
(4) Creeping.
(5) Crawling.
See Cover & Movement which covers "drop to prone", creeping and crawling from the Basic Training Handbook 1945