17.—Double sentinels.
Post double sentinels in each section, each man watching in turn, the other resting but within call.
18.—Silence.
They should refrain from making the least noise so as to hear and not be heard.
19.—No firing when fired upon.
There should be no firing when the enemy fires since when the enemy fires, he does not advance.
20.—Look and listen.
They should keep a sharp lookout but listen even more attentively.
21.—In the listening posts.
Sentinels in the listening posts should listen especially for the noise of crushed branches, stirring leaves, slight noise of arms or utensils.