| Problemss In Society | Academic & Science |
| Phuket International School (Quality Schools International) | Academic & Science |
| Process Interface System | Academic & Science |
| Process, Interrupts, Signals | Academic & Science |
| Poitiers | Airport Code |
| Property Investment Service | Business |
| Project Information System | Business |
| Progressive Induction System | Business |
| Perfectly Inelastic Supply | Business |
| Professional Investment Services | Business |
| Portfolio Investment Scheme | Business |
| Precision Investment Services | Business |
| Permanent Island School | Community |
| Politiets Indsats Styrke | Community |
| Passenger Information System | Computer Technology |
| Processing Information Structure | Computing |
| Project Implementation Schedule | Computing |
| Protocol Interfaces | Computing |
| Physical Interfaces | Computing |
| Personal Information Protection System | Computing |
| Privacy Invasive Software | Computing |
| Polkainsure Finance | Cryptocurrency |
| Payment Initiation Services | General |
| Prescribing Information System | General |
| Poster Induced Stupidity | General |
| Participant Information Sheet | General |
| Penning Ionization Spectroscopy | General |
| Plant Inspection Stations | General |
| Product Information Sheets | General |
| Point of Initial Slippage | General |
| Physical Inspection Scores | General |
| Penguins In Space | General |
| Product Information System | General |
| Police Interceptor Sedan | General |
| Programa de Integração Social | General |
| Prawo i Sprawiedliwość | General |
| Personal Information System | General |
| Plot Induced Stupidity | General |
| Premier Ibrahim Sultan | General |
| Politeknik Ibrahim Sultan | General |
| Party in Saigon | General |
| Provider of Independent Service | General |
| Pinnacle Infotech Solution | General |
| Personnel Identification System | General |
| Poslovni Informacioni Sistemi | General |
| Polities Indsats Styrke | Governmental |
| Post Imprisonment Supervison | Governmental |
| PISKA | Indian Railway Station |
| Perfect Is S*** | Internet |
| Personnel Information System | Manipur Government |
| Patient Information Sheet | Medical |
| Pharmacy Information Systems | Medical |
| Protease Inhibitors | Medical |
| Pharmacy Information System | Medical |
| Please Ignore Seriously | Messaging |
| Poitiers, France | Regional |
