| Abbreviation | Definition |
|---|---|
| FFL | Fayetteville Free Library |
| FGDL | Florida Geographic Data Library |
| FGDL | Florida Geographical Data Library |
| FGL | Functional Graph Library |
| FGLF | Forest Grove Library Foundation |
| FHCBL | Frederick H. Cossitt Branch Library (North Granby, CT) |
| FHCL | Fraser Hill Community Library |
| FHL | Family History Library |
| FHL | Friday Harbor Library |
| FIN | Free Information Network |
| FizAktVesh | Fiziologicheski Aktivnye Veshchestva (Physiologically Active Substances) |
| FJPL | Friends of the Jacksonville Public Library |
| FL | Faith Library |
| FL | Flux Library |
| fl. | flourished (biog dates) |
| FLA | Florida Library Association |
| FLA | Foothills Library Association |
| FLANN | Fast Library for Approximate Nearest Neighbors |
| FLANN | fast library for approximate nearest neighbours |
| FLC | Fenway Library Consortium |