POSI
| 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 |