1. Behavior of enemy during period preceding relief, and any point in their line requiring special information, e.g., enemy may have cut wire as though preparing to attack.
Plate 42.
2. Machine-gun emplacement may be suspected at some particular point.
3. Anything ascertained by patrols about ground between firing lines, thus avoiding unnnecessary reconnaissance.
4. Any standing arrangements for patrols at night, including point at which wire can best be passed, ground to be patrolled, or place where they can lie under cover.
5. Any parts of trench from which it is not safe to fire. Such positions are apt to occur in winding trenches, and are not always recognizable in the dark.
6. Special features of trench, recent improvements, work not completed, dangerous points (on which machine guns are trained at night), useful loopholes for observation.
7. Places from which food and water can be safely obtained.