What does the 11th General Order of a Sentry emphasize a need for?

The 11th General Order of a Sentry specifically emphasizes the importance of being particularly vigilant during nighttime hours. This focus is crucial because nighttime presents unique challenges in surveillance and security. Visibility is limited, making it harder to detect potential threats. Therefore, a heightened state of alertness is necessary to ensure the safety of the area being patrolled. This understanding reinforces the principle that sentries play a vital role in security, particularly when conditions are less favorable for observation.

The other choices involve important aspects of sentry duty, such as the necessity of constant patrolling, documenting observations, and maintaining communication, but they do not reflect the specific emphasis placed on vigilance during nighttime, which is a critical component of effective sentry duty as outlined in the 11th General Order.