| Abbreviation | Definition |
|---|---|
| CI | Colegio de Ingenieros de Chile |
| CI | College of Engineers of Chile |
| CI | Combustion Institute |
| CIA | Concrete Institute of Australia |
| CIA | Institut Canadien des Actuaires |
| CIAPR | Colegio de Ingenieros y Agrimensores de Puerto Rico |
| CIAPR | College of Engineers and Surveyors of Puerto Rico |
| CIAS | Cornell International Affairs Society |
| CIB | Conseil International du Bâtiment pour la Recherche, l'Étude et la Documentation |
| CIB | Conseil International du Btiment pour la Recherche, l'tude et la Documentation |
| CIB | International Council for Building Research Studies and Documentation |
| CIBSE | Chartered Institution of Building Services Engineers |
| CIC | Institut de Chimie du Canada |
| CICHE | - (4)å x |
| CICHE | Chinese Institute of Civil and Hydraulic Engineering |
| CICHE | Zho¯ngguo´ Tu?mu` Shui?li` Go¯ngche´ng Xue´hui` |
| CICHE | Zhongguo Tu mu Shui li Gongcheng Xuehui |
| CICHE | Zhongguo Tumu Shuili Gongcheng Xuehui |
| CIDS | Central Iowa Dalily Society |
| CIDS | Central Iowa Daylily Society |