| Abbreviation | Definition |
|---|---|
| fld | fold, folded |
| fld. | folded |
| fldg. | folding |
| FLIN | Federal Library and Information Network |
| FLIP | Fire Library Improvement Process |
| FLLS | Finger Lakes Library System |
| FLO | Fenway Libraries Online |
| FLO | Fenway Library Organization |
| FLOW | Flexible Library for Optimised Wireframing |
| FLOW | Flexible Library For Optimized Wireframing |
| FLP | Free Library of Philadelphia |
| FLPL | Florence Lauderdale Public Library |
| FLPL | Friends of the Lawrence Public Library |
| FLS | Friends of Libraries Section |
| FLTL | Finger Lakes Toy Library |
| FluorChemRev | Fluorine Chemistry Reviews |
| FM | Field Manual |
| FMLA | Fellow of the Medical Library Association |
| FO | first occurrence |
| FOAL | Friends of Appleton Library |