Naval Knowledge — NROTC Guide

Salute all officers when you are covered — and return every salute you receive. Uncovered, acknowledge with a greeting instead of saluting. When in doubt, salute.
Address officers as "Sir" / "Ma'am" or by rank and name.
Cover (your hat) goes on outdoors and comes off indoors — unless you are under arms or on duty, in which case you stay covered.
Stand at attention when a senior officer enters the room; the first to see them calls "Attention on deck."
Hands in pockets: the Navy authorized it in 2024, as long as it doesn’t compromise safety or the rendering of honors — the Marine Corps still prohibits it.
Gum: no chewing gum in uniform. Marines are prohibited by MCO P1020.34H; sailors fall under the Navy’s ban on eating while walking in uniform.

Memorize these. You'll recite them during inspections:

To take charge of this post and all government property in view.
To walk my post in a military manner, keeping always on the alert and observing everything that takes place within sight or hearing.
To report all violations of orders I am instructed to enforce.
To repeat all calls from posts more distant from the guardhouse than my own.
To quit my post only when properly relieved.
To receive, obey, and pass on to the sentry who relieves me all orders from the commanding officer, field officer of the day, officer of the day, and officers and petty officers of the watch.
To talk to no one except in the line of duty.
To give the alarm in case of fire or disorder.
To call the petty officer of the watch in any case not covered by instructions.
To salute all officers and all colors and standards not cased.
To be especially watchful at night and during the time for challenging, to challenge all persons on or near my post, and to allow no one to pass without proper authority.

Source: U.S. Navy General Orders of a Sentry