Which authority prescribes the number of sentry posts?

The authority that prescribes the number of sentry posts is the Commanding Officer. The Commanding Officer holds the ultimate responsibility for the unit's security and operational readiness, and they consider a variety of factors such as the size of the area being secured, the mission requirements, and the resources available when determining how many sentries are necessary. This ensures that adequate security measures are in place to protect personnel and equipment.

While other ranks, such as the First Sergeant, Platoon Leader, and Sergeant Major, play vital roles in the execution of orders and the day-to-day management of tasks, the responsibility for establishing the number of sentry posts lies squarely with the Commanding Officer, who sets the overall security posture of the unit.