English abbreviations from fn to fo
- FN (Fabrique Nationale (Manufacturer))
- FNA (Functional Needs Analysis)
- FNAC (Fine Needle Aspiration Cytology)
- FNAWS (Foundation For North American Wild Sheep)
- FNB (Neubrandenburg Airport)
- FNBA (Flexible Narrow Beam Adapter)
- FNBDT (Future Narrow Band Digital Terminal)
- FNBVT (Future Narrow Band Voice Terminal)
- FNC (Madeira Airport)
- FND (Friday Night Drawing)
- FNE (Fane Airport)
- FNF (Fight No Further)
- FNG (Fucking New Guy)
- FNH (Fincha Airport)
- FNHH (Friday Night Hardcore Havoc)
- FNI (Garons Airport)
- FNJ (Pyongyang Sunan International Airport)
- FNL (Fort Collins-Loveland Municipal Airport)
- FNMOD (Fleet Numerical Meteorological and Oceanographic Detachment)
- FNN (Feed-forward Neural Network)
- FNOC (Fleet Numerical Oceanographic Command)
- FNP (Florida Newspaper Project)
- FNPG (Friends of the National Parks at Gettysburg)
- FNR (Funter Bay Seaplane Base)
- FNS (Food and Nutrition Service)
- FNSL (Frogans Network System Language)
- FNSRO (Food and Nutrition Service Regional Office)
- FNT (Bishop International Airport)
- FNW (Far North Wrestling)
- FO (Forward Observer)
- F.O. (Flight Officer)