| Florida Irrigation Society | Academic & Science |
| Financial Information Strategy | Accounts and Finance |
| Free In Store | Accounts and Finance |
| Financial Investment Services | Business |
| Financial Information System | Business |
| Fission Energy Ltd | Business |
| Finance Information System | Business |
| Finance Information Server | Business |
| Frankfurt International School | Community |
| Festival Information System | Community |
| Franconian International School | Community |
| Frame Information Structure | Computer Hardware |
| Fingerprint Identification System | Computing |
| Full Information System | Computing |
| File Input Stream | Computing |
| Factory Installation Services | Computing |
| Forms Interchange Standard | Computing |
| Fundamental Information Services | Computing |
| Stafi | Cryptocurrency |
| Fault Isolation System | Electronics |
| Front Islamique du Salut | General |
| Faculty of Information Studies | General |
| Faulr Isolation System | General |
| Fernerkundung in Schulen | General |
| Flight Information Services | General |
| Federal Inspection Station | General |
| Founders Imperial Stout | General |
| Fast Innovative Solutions | General |
| Fatigue Impact Scale | General |
| Fuel Injection System | General |
| Front Impact Sensor | General |
| Ford Interactive System | General |
| Fuji International Speedway | General |
| Fleet Information System | General |
| Fast Idle Solenoid | General |
| Fuel Injection Seal | General |
| Fast Idle Speed | General |
| Fahrer Informations System | General |
| Fuel Intake Sensor | General |
| Fleet Information Software | General |
| First Inertia Switch | General |
| Fleet Information Service | General |
| Fully Independent Suspension | General |
| Flexible Inspection System | General |
| Fuzzy Inferencing Systems | General |
| Foundation for Infinite Survival | General |
| Fairway Information Services | General |
| Fiber Instrument Sales | General |
| Foundation for International Services | General |
| Funding Information System | General |
| Fiscal Impact Statement | General |
| Front Islamique De Salut | General |
| Ftp Interface Service | General |
| Factory Information System | General |
| Free Into Store | General |
| Factory Information Services | General |
| Field Information System | Governmental |
| Flood Insurance Study | Insurance |
| Frente Islámico de Salvación | International |
| Future Internet Symposium | Internet |
| Fitness Instructor Specialist | Jobs |
| Fusion Inhibitors | Medical |
| Foal Immunodeficiency Syndrome | Medical |
| Fake Information System | Messaging |
| Friendly Information System | Military and Defence |
| Flight Information Service | Military and Defence |
| Foreign Intelligence Service | Military and Defence |
| Facility Interface Sheet | Space Science |
| for International Ski | Sports |
| Federation International De Ski | Sports |
| Federation of International Skiing | Sports |
| Federation Internationale De Ski | Sports |
| The Federation Of International Skiing | Sports |
| Fixed Income Securities | Stock Exchange |
