(c) Natural obstacles as mechanized attack.
(d) Artificial obstacles, tions, and other devices, against mechanized attack.
such as mines, demoli- to provide protection
(e) Warning devices, such as trip flares and noise-makers, designed to give warning of the ap- proach of an enemy.
(f) Warning system, including observation posts, listening posts, patrols, and alarm system, to give warning of air, airborne, mechanized, or ground attack.
(g) Interior guard to maintain discipline, sound alarm in case of gas attack, and give warning of enemy who have eliminated or eluded the outer ob-
servation posts. (h) Organization of available
weapons into combat groups to facilitate control.
(i) Designation of assembly points where combat groups may assemble upon warning of an attack.
(j) Foxholes for all personnel, sited for close-in defense of vehicles, close-in defense of installations, and for the perimeter defense.
(k) Individual defense can best be accomplished from the foxhole each individual prepares near his work site.
(1) Vehicular defense is the duty of the driver and may frequently be conducted from a foxhole in