Precision Approach Radar 
photosynthetically active radiation 
Performance and Accountability Report 
Perimeter Acquisition Radar 
Performance Analysis and Review 
Pulse Acquisition Radar 
Participatory Action Research 
Preferential Arrival Route 
Partmo 
Parts Master 
peak to average ratio 
Problem Action Record 
Program Appraisal and Review 
Project Authorization Request 
Protective Action Recommendation 
Payload Accommodations Requirements 
Pennsylvania Advanced Reactor 
Performance and Accountability Reports 
performance appraisal report 
Performance Assurance Requirements 
Personnel Action Request 
population at risk 
Purchasing approval request 
Packet-to-Average Ratio 
paragraph 
Parallel 
PARAMETER 
Parent 
parenthesis 
Pension adjustment reversal