What does the 3rd General Order require of a sentry?

The third general order requires a sentry to quit their post only when properly relieved. This is important for maintaining the integrity and security of the watch. A sentry is responsible for the vigilance of their assigned area and must ensure that there is always someone to assume that responsibility. Quitting the post without proper relief could lead to a security lapse, allowing unauthorized access or other issues to arise in the area the sentry is guarding. Therefore, understanding and adhering to this order helps reinforce the chain of command and ensures readiness and safety within the operational environment.

The other options, while related to a sentry's duties, do not specifically embody the essence of the third general order. Reporting violations, keeping an area hazard-free, and saluting officers and colors are all important aspects of a sentry's responsibilities, but they relate more closely to other general orders and guidelines within military protocol.