A+R stands for azithromycin plus rifampin
A+I stands for aldosterone plus insulin
A-4 stands for Douglas Sky Hawk Attack Bomber (Vietnam)
A-76 stands for OMB Circular No. A-76 (Revised Supplemental Handbook Performance of Commercial Activities)
A-A stands for Disney's Audio-Animatronics
A-ACS stands for American-Austrian Cultural Society (est. 1954; Washington, DC)
A-ARM stands for Army Armor Board (Fort Knox, KY)
A-AUC stands for absolute area under the absorption curve
A-AR stands for Army Artillery Board (Fort Sill, OK)
A-ARCS stands for Arctic Atmospheric Radiation and Cloud Station