4. _Marching Reliefs._--Reliefs of fewer than four men will be formed in single rank, when of four men, or upwards, they will be formed into two ranks. (In streets, or narrow places, reliefs should always be marched in single rank.) When marching in line, the corporal will be on the right; when in file (or as in file) he will be on the right of the rear file (or man). =204.= _Sentries challenging._ 1. When it becomes dark the sentries will challenge in the following manner: On the approach of a person the sentry will call out in a sharp tone, _Halt. Who comes there?_ when on a post where a sudden rush could be made upon him, he will at once come to the “_Engage_,”[12] but without drawing back the right foot, if the person approaching gives a satisfactory reply, the sentry will say _Pass friend; All’s well_, remaining at the _Engage_ till he has passed. If the person approaching answers GRAND (_or_ VISITING) ROUNDS, the sentry, if there is no countersign, will say _Pass grand_ (or _visiting_) _rounds: All’s well_; presenting arms as they pass if they are grand rounds. But if there is a countersign he will say _Stand grand_ (or _visiting_) _rounds: Advance one and give the countersign_, at the same time coming down to the _Engage_. In this position he will receive the countersign; and if it is correct will say _Pass grand_ (or _visiting_) _rounds; All’s well_; and proceed as above described. 2. If the sentry is on or near the guard-room door, he will proceed as in =205=. =205.= _Guards turning out at night._ The following form will be observed when a guard is visited by the field officer or captain of the day, termed grand or visiting rounds:-- On their approach the sentry at or near the guard-room door will challenge: _Halt; who comes there?_ The officer will reply, GRAND (_or_ VISITING) ROUNDS; the sentry will then call: _Guard--turn out_. The guard will fall in with bayonets fixed and arms sloped, and, if there is no countersign, the commander will call out: _Advance, grand_ (or _visiting_) _rounds; All’s well_; to grand rounds he will present; to visiting rounds he will remain at the slope.