8.  In digging, not enough care was used to conceal the fresh earth from the enemy.  Make false emplacements to utilize this dirt; also dig dummy trenches about one foot deep, leaving the sides sharp so that they will show clearly on aerial photographs.

9.  In using plants as camouflage, distinct care must be exercised not to put growing plants too freely nor to place them where they never existed.  The actual ground conditions must be copied.

10.  Some latrines were not arranged with the stools close beneath the wall nearest the enemy.  This caused the loss of protection, which it is imperative to consider, as many casualties occur here.

11.  Too many listening posts.  They are easily captured by hostile fighting patrols.  There should never be more than two listening posts to a battalion.

12.  The observation stations in many instances had no good field of fire or were outlined against the sky on the crest of some rise.  The site for an observation post should always be placed over the crest and have a good field of fire for use in case of attack.

Occupation.

I. Relief in the Trenches.

A. THE TWO MAIN CLASSES OF RELIEF: 
1.  General Relief.  Applied to the relief of a whole position
manned by a division or more.  Executed when large units are
going to “full rest” in the rear or being removed from one
part of the front to another.  Executed in the same way as
interior relief; i.e., by successive relief of the
battalions involved.
2.  Interior Relief.  Applied to the relief of one sector or
portion of a sector manned by a brigade or less.

B. GENERAL PRINCIPLES OF RELIEF: 

1.  Interior relief is executed about once every six days; more
frequently when the stay in the trenches is particularly
arduous, less frequently when it is unusually comfortable.
2.  The battalion is the relieving unit.
3.  It is advisable to arrange the relief between units which
have friendly relations to one another; e.g., battalions of
the same regiment; and, so far as possible, to assign each
unit to the same trenches on each relief.  This promotes
continuity of effort.
4.  Relief is executed at night; the hour must be varied; secrecy
is imperative.
5.  Prompt execution is essential, to prevent fatigue of the
troops and congestion of the boyaux.

C. THE MECHANISM OF RELIEF: 

1.  Reconnaissance, 24 hours in advance, by the captain of each
relieving company, accompanied by his platoon leaders and
non-commissioned officers.  He ascertains: 
(1) The plan of occupation; i.e., the dispositions and
duties of the unit to be relieved.
(2) The shelter accommodations.
(3) Work being done and proposed.
(4) Condition of the wire and other defences.
(5) The available water supply.
(6) Artillery support.
(7) Communications.