Application acoustic phase plate Advance Procurement Plan Annual Performance Plan appendix Application Portability Profile Approach AUXILIARY POWER PLANT Accident Prevention Program Advanced Procurement Package Agency Peculiar Property Allied Procedural Publication amyloid-precursor protein apparatus apparent Application Program applications portability profile appointment Apprehend Approach Control Approach Control Service Approved Ascend Password Protocol Associative Parallel Processor attached payload pallet A Posteriori Probability A4 precursor protein A4 protein precursor A4-amyloid precursor protein A4-amyloid protein precursor