| Acronym | Definition |
|---|
| POSI➣Promoting Conference for Osi |
| POSI➣Programa Operacional da Sociedade de Informação (Portugal) |
| POSI➣Partido Obrero Socialista Internacionalista (Spanish: International Socialist Workers Party; Spain) |
| POSI➣Public Offering of Securities Insurance |
| POSI➣Promoting Conference for OSI (Open Systems Interconnection) |
| POSI➣Publisher Out of Stock Indefinitely |
| POSI➣Promoting Open System Interface |