| Abbreviation | Definition |
|---|---|
| CARL | California Academic Research Libraries |
| CARL | California Academic Research Library |
| CARL | Canadian Association of Research Libraries |
| CARLI | College And Research Libraries of Illinois |
| CARLI | Consortium of Academic and Research Libraries in Illinois |
| CAS | Current Awareness Service |
| CASL | Canadian Association for School Libraries |
| CASL | Council Of Australian State Libraries |
| CASSI | CAS Source Index |
| CATNYP | Catalog of The New York Public Library |
| CBEC | Childrens Book Exhibit Center |
| CBL | Chester Beatty Library |
| CBR | Comic Book Reader |
| CBRL | Cape Breton Regional Library |
| CBUP | Catalogo Bibliografico Unico Provinciale |
| CC | Creative Commons |
| CC0 | "No copyright reserved" mark |
| CC0 | Creative Commons Zero |
| CCA | Canadian Council of Archives |
| CCAD | Canadian Committee on Archival Description |