Pelvic Inflammatory Disease 
Proportional Integral Derivative 
Packet Identifier 
plan identification number 
Proportional Integral Differential 
Payload Insertion Device 
process ID 
parameter identification 
Prime Item Development 
Project Information Document 
Proportional Integral Derivation 
pain intensity differences 
partial initial decision 
Photoionization Detector 
Planned Industrial Development 
Process Identifier 
Product ID 
Product IDentification 
Product IDentifier 
Program Information Document 
Program Introduction Document 
Project IDentification 
Project Initiation Document 
prolapsed intervertebral disc 
Proportional Integral and Derivative 
Proportional-Integral-Derivative 
Public Information Division 
Packet ID 
Packet Idendifier 
Packet IDentification