You know what fk it lets milsim with batman, as the military discribes batmen.
A batman (or batwoman) is a soldier or airman assigned to a commissioned officer as a personal servant. Before the advent of the automobile, an officer's batman was also in charge of the officer's bathorse that carried the packsaddle with his officer's kit during a campaign.
The term is derived from the obsolete bat, meaning "packsaddle" (from French bāt, from Old French bast, from Late Latin bastum) + man.
A batman's duties often include:
acting as a "runner" to convey orders from the officer to subordinates
maintaining the officer's uniform and personal equipment as a valet
driving the officer's vehicle, sometimes under combat conditions
acting as the officer's bodyguard in combat
other miscellaneous tasks the officer does not have time or inclination to do
The action of serving as a batman was referred to as "batting". In armies where officers typically came from the upper class, it was not unusual for a former batman to follow the officer into later civilian life as a domestic servant.