SQUAD.--Extend the arm horizontally toward the platoon leader; swing the hand, up and down from the wrist. RUSH.--Same as _double time_. The signals PLATOON and SQUAD are intended primarily for communication between the captain and his platoon leaders. The signal PLATOON or SQUAD indicates that the platoon commander is to cause the signal which follows to be executed by platoon or squad. CHAPTER 12. Guard Duty. Time spent: Study, 2 hours. Conference, 2 hours. Formal guard mounting. Guards are divided roughly into four classes: 1. Exterior--(Which come more properly under head of field service). 2. Interior--Their purpose is to preserve order, protect property and enforce police regulations. 3. Military Police--Also treated of in field service. 4. Provost Guards--Used in the absence of military police to aid civil authorities in preserving order among soldiers beyond the interior guard. Here we are concerned chiefly with interior guards. We shall make up a brief summary of what an officer must know and what he ought to teach his non-coms. and men. Also we shall touch upon the subject of guard duty as it has been changed by trench warfare. An officer ought to have a good grasp of the following subjects relative to guard duty: 1. Guard mounting (both formal and informal). 2. Posting reliefs. 3. Preparation and running of rosters. 4. General orders--also special orders at post No. 1. 5. Duties of the following in reference to guard duty: 1. Commanding officer. 2. Officer of the day. 3. Adjutant. 4. Sergeant Major. 5. Commander of the guard. 6. Sergeant of the guard. 7. Corporal of the guard. 8. Musicians. 9. Orderlies and color sentinels. 10. Privates of the guard. 6. Compliments of the guard. 7. Prisoners: General. Garrison. Awaiting trial. Awaiting result of trial. How is an officer arrested? Can an enlisted man arrest him? How is a non-com. arrested? How is a soldier arrested? How is a civilian arrested? (See a.w. No. 68.) An officer ought to-teach to his non-coms. as much of the above as is consistent with time and other demands; he ought to teach to his privates all that is necessary to the proper discharge of their duties in this connection. FORMAL GUARD MOUNTING.--Here follow a few reminders that may help the reader to keep the ceremony in mind: 1. Weather conditions permitting, guard mounting takes place every day at the discretion of the C.O. 2. Tour of duty is 24 hours; there are 3 reliefs, 2 hours on and 4 hours off. No organization is detailed for guard duty more than once in 5 days if this can be prevented. CEREMONY.--1. The band takes post, its left 12 paces to the right of where the right of the guard is to be.