=12.= When the guard is detailed from several organizations, rosters will be kept by the adjutant, of officers of the day and officers of the guard by name; by the sergeant major under the supervision of the adjutant, of sergeants, corporals, musicians, and privates of the guard by number per organization; and by first sergeants, of sergeants, corporals, musicians, and privates by name. (See Appendix A.) =13.= When organizations furnish their own stable, or stable and park guards, credit will be given each for the number of enlisted men so furnished as though they had been detailed for main guard. =14.= Special guards, other than stable or park guards, will be credited the same as for main guard, credited with fatigue duty, carried on special duty, or credited as the commanding officer may direct. (Pars. 6, 221, 247, and 300.) =15.= Captains will supervise the keeping of company rosters and see that all duties performed are duly credited. (See pars. 355-364, A. R., for rules governing rosters, and Form 342, A. G. O., for instructions as to how rosters should be kept.) =16.= There will be an officer of the day with each guard, unless in the opinion of the commanding officer the guard is so small that his services are not needed. In this case an officer will be detailed to supervise the command and instruction of the guard for such period as the commanding officer may direct. =17.= When more than one guard is required for a command, a field officer of the day will be detailed, who will receive his orders from the brigade or division commander, as the latter may direct. When necessary captains may be placed on the roster for field officer of the day. =18.= The detail of officers of the guard will be limited to the necessities of the service and efficient instruction; inexperienced officers may be detailed as supernumerary officers of the guard for purposes of instruction. =19.= Officers serving on staff departments are, in the discretion of the commanding officer, exempt from guard duty. =20.= Guard details will, if practicable, be posted or published the day preceding the beginning of the tour and officers notified personally by a written order at the same time. =21.= The strength of guards and the number of consecutive days for which an organization furnishes the guard will be so regulated as to insure privates of the main guard an interval of not less than five days between tours. When this is not otherwise practicable, extra and special duty men will be detailed for night guard duty, still performing their daily duties. When so detailed a roster will be kept by the adjutant showing the duty performed by them. =22.= The members of main guards and stable and park guards will habitually be relieved every 24 hours. The length of the tour of enlisted men detailed as special guards, other than stable or park guards, will be so regulated as to permit of these men being held accountable for a strict performance of their duty.