Italian principles for the combined operations of parachute and air-landing troops make the following specifications: (1) Air-landing units should be composed of troops which have received special training. (2) This training should consist of practice in rapidly deplaning, and should be carried out jointly with parachute troops. (3) Air-landing troops require special equipment and organization. (4) The employment of air-landing units in cooperation with parachute units will normally be "to occupy important positions in the rear of the enemy in order to assist the advance of friendly troops, cut off the enemy's retreat, or prevent the flow of reinforcements to the enemy."