Robert Stupart

“ A sentry will only challenge a person or party approaching his post when it is necessary for his own safety, when he is doubtful as to whether the person or party approaching is authorised to pass, when it is ordered for a special reason, such as in the case of a sentry posted on a fortress or prison, or when there is a countersign to be delivered.
2. When challenging on the part of a sentry is necessary, it will be carried out as follows:—
i.⁠When a person or party approaches the post, the sentry will, as soon as the person or party is within speaking distance, call out, Halt—Advance one ”

“ The file will then double back to the guard, and rounds will advance to the guard, which will present arms to grand rounds.
Sentries Paying Compliments.
On the approach of an officer, when he is at least fifteen paces distant, a sentry, if on the march, will halt, and turn to the front; if standing at ease, he will come to attention and “slope.” To field officers and other officers of the Army and Navy entitled to the salute, he will present arms. ”