| Acronym | Definition |
|---|
| CIRN➣Community Informatics Research Network (est. 2003) |
| CIRN➣Club Italiano Razze Nordiche (Italian: Italian Club of Northern Breeds; est. 1976; Milan, Italy) |
| CIRN➣Clinical Information Resource Network |
| CIRN➣Carpathia Intelligent Routing Network (Carpathia Hosting, Inc.; Virginia) |
| CIRN➣Commanders Information Reporting Network |
| CIRN➣Center of Industrial Relations and Negotiations (est. 2003; Greece) |