What must personnel be instructed on if authorized to carry arms?

Personnel authorized to carry arms must be thoroughly instructed on orders to sentries and the circumstances under which they may fire their weapons. This training is critical because it ensures that armed personnel understand their responsibilities and the legal and operational parameters surrounding the use of firearms. Such knowledge is essential for maintaining safety and discipline, minimizing the risk of accidents, and ensuring compliance with regulations.

Understanding orders to sentries includes recognizing when to engage and how to respond to various situations appropriately, which is paramount in maintaining security and order. This training plays a vital role in enabling personnel to act decisively and correctly in high-pressure scenarios, thereby safeguarding both personnel and civilians.

The other options, while potentially important in different contexts, do not address the immediate need for responsible engagement with a firearm in operational environments, making them less relevant in this specific context of carrying arms.