The 3 General Orders
1. I will guard everything within the limits of my post and quit my post only when properly relieved. 2. I will obey my special orders and perform all of my duties in a military manner. 3. I will report violations of my special orders, emergencies, and anything not covered in my instructions, to the commander of the relief.
What it actually means
The Army and Air Force take the same guard-duty philosophy the sea services spread across eleven orders and compress it into three. Every Army and Air Force recruit memorizes these in Basic Combat Training / BMT. The logic is identical: guard your post, follow your specific instructions, and escalate anything you cannot handle. Shorter list, same reflex.
Where it came from
The three general orders are the Army standard and are also taught in Air Force Basic Military Training. They are the condensed counterpart to the sea services’ eleven general orders of a sentry.
U.S. Army general orders (also used by the Air Force) — reference