| FLIRT | Fast Library Identification And Recognition Technology 
| Others |
| FLIRT | Fast Light Innovative Regional Train
| Others |
| FLIRT | Find Love In Real Time
| Others |
| FLIRT | Finding Love In Real Time
| Others |
| FLIRT | First Ladies International Racing Team
| Others |
| FLIRT | Flexible Lightweight Innovative Regional Train
| Others |
| FLIRT | Flinker Leichter Innovativer Regional Triebzug
| Others |
| FLIRT | Flinker Leichter Inovativer Regional Triebzug
| Others |
| FLIRT | Fmribs Linear Image Registration Tool
| Others |
| FLIRT | Focus Language Incentives Rules and Tools
| Others |
| FLIRT | Fortis Levis Iucunda Rapida Transeat
| Others |
| FLIRT | Free Living Intense Recreation Troupe
| Others |