ne
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.
(8) The location, amount and condition of stores.
(9) Danger points.
(10) All available information of the enemy; his habits,
location of his snipers, what work he is doing.
(11) The ways and means of liaison, both lateral and from
front to rear.
To the success of this reconnaissance, the closest
co-operation between all officers of the companies
relieving and relieved, is indispensable.

2. The march from billets to the trenches:
(a) Transportation, by auto-trucks and wagons, is utilized
to a point as near the lines as possible, to carry the
packs of the men, the auto rifles, extra ammunition and
other heavy equipment. When the distance is gre