Retail Price Index 
Rensselaer Polytechnic Institute 
Real Property Inventory 
Radio Plasma Imager 
Retail Prices Index 
Rod position indicator 
Radio Physical Interface 
Railway Progress Institute 
Remote Principal Investigator 
Revolution per Inch 
Rockwell Protocol Interface 
Runway Point of Intercept 
Radar Precipitation Integrator 
Radio Port Intermediary 
Radio Press International 
radius polydispersity index 
rapidly progressing infection 
Ratings Percentage Index 
Read Punch and Interpret 
Recruiting Publicity Item 
Régie Publicité Industrielle 
regional perfusion index 
Regulatory program integration 
related proteins of the immune system 
Relative Performance Index 
relative position indication 
relative proliferation index 
Release from Proactive Interference 
Remote Packet Interface 
Remote Position Indicator