| Abbreviation | Definition |
|---|---|
| CSHL | Cold Spring Harbor Library |
| CSIL | California Spatial Information Library |
| CSL | Colorado State Library |
| CSLA | California School Library Association |
| CSLA | Church and Synagogue Library Association |
| CSLF | California State Library Foundation |
| CSLL | Chico Seed Lending Library |
| CSLP | Collaborative Summer Library Program |
| CSM | Christian Science Monitor |
| CSPL | Carnegie Stout Public Library |
| CSS | Corpus Sentence Search |
| CTCL | Community and Technical College Libraries |
| CTL | C TOC2 Library |
| CTLC | Carolinas Theological Library Consortium |
| CTLC | Cross Timbers Library Collaborative |
| CTLS | Central Texas Library System |
| CTPL | C Thread Pool Library |
| CTPL | Central Technical Publication Library |
| CTPL | Central Technical Publications Library |
| CTPL | Charlestown Township Public Library |