There are several things a sentry must know in order to perform their role:
- Locations of:
- Neighbouring posts;
- Own backup; and
- Covering sentries.
- Length of time of duty and what time it will start.
- Method of relief.
- Who is taking over from you; and
- How will they know?
- Situation of enemy forces.
- Arcs of observation.
- Arcs of fire.
- Location of mines, trip flares and other local defences.
- Action on suspicious movement.
- Method of alerting troops.
- Method of challenging.
- Procedure on hearing correct password.
- Procedure on hearing incorrect password.
- Orders for opening fire.
- Information on friendly patrols coming in or going out.
- Concealment (of own position).
- Questions (you as the sentry may wish to ask).
- Current password; and
- If changing, new password and time of change.
The first person posted as a sentry will draw a sketch of the surrounding area noting buildings, dead ground, arcs of fire among other details.
A sentry will also provide passive reconnaissance, logging the movement of people and vehicles.