D. The-non-commissioned officer coming on duty will go round and post new sentinels with the non-commissioned officer coming off duty.
E. The length of the tour of duty will depend upon the number of officers and non-commissioned officers on duty. Normally each tour should be, by night, two hours; by day, four hours. This may be modified, however, so that all officers and non-commissioned officers will have an equal amount of this duty while in the trenches.
F. Non-commissioned officers, after posting sentinels, will report "all is well" or otherwise to the officers on duty.
G. No man will be detailed for a duty in the trench without being given suitable warning of this duty and be informed at which hour he will come on duty.
H. The Company Commander will be responsible for sending any report required by Battalion Headquarters.
2. Sentries.—A. The number of sentry posts required will depend on the assumed propinquity or distance of the enemy, strength of obstacles, ease with which sentry posts can be re-enforced and other local conditions. Normally by day this should be one sentinel for each platoon and at night three double sentinels for each platoon. There must be sentries enough to insure alarm being given promptly in case of attack and that local resistance is sufficient until help can arrive.
B. The next relief will remain within an easy distance of the sentry on post, usually in shelters provided for this purpose.
C. Every sentry is to be regularly posted by a non-commissioned officer who will explain to him his duties and ascertain that the sentry is aware of the position of the section and platoon commanders and of the sentries on either side, and whether there are any patrols or working parties out in front.
D. Every sentinel will report when an officer passes his post, "All is well," or otherwise.
E. Every sentinel by day will be provided with a head-cover to blend with the ground (this may be improvised), and while observing the ground to the front will remain perfectly still. An empty sand bag or some other suitable material may be utilized for this purpose.