| F | Female | |
| F2F | Face To Face | |
| F2T | Free To Talk | |
| FAQ | Frequently Asked Question(s) | |
| FAWC | For Anyone Who Cares | |
| FC | Fingers Crossed | |
| FCFS | First Come, First Served | |
| FCOL | For Crying Out Loud | |
| FF | Freeze Frame | |
| FFWE | Finds Fault With Everything | |
| FH | Freaking Heck | |
| FIL | Father-In-Law | |
| FISH | First In, Still Here | |
| FITB | Fill In The Blanks | |
| FMTYEWTK | Far More Than You Ever Wanted To Know | |
| FNB | Football And Beer | |
| FO | Far Out | |
| FOAD | Freak Out And Die | |
| FOAF | Friend Of A Friend | |
| FOCL | Falling Off Chair Laughing | |
| FOFL | Falling On Floor Laughing | |
| FOFLMAO | Falling On The Floor Laughing My Head Off | |
| FOMCL | Falling Off My Chair Laughing | |
| FOTFL | Falling On The Floor Laughing | |
| FOTFLMAO | Falling On The Floor Laughing My Head Off | |
| FOTFLOL | Falling On The Floor, Laughing Out Loud | |
| FS | For Sale | |
| FTASB | Faster Than A Speeding Bullet | |
| FTBOMH | From The Bottom Of My Heart | |
| FTF | Face To Face | |
| FTG | For The Group | |
| FTL | Faster Than Light | |
| FTMP | For The Most Part | |
| FTP | File Transfer Protocol | |
| FTR | For The Record | |
| FTW | For The Win | |
| FUBAR | Fouled Up Beyond All Repair | |
| FUBB | Fouled Up Beyond Belief | |
| FUD | Fear, Uncertainty And Doubt | |
| FUD | Fear, Uncertainty, And Doubt | |
| FURTB | Full Up Ready To Burst | |
| FUT | Follow Up To | |
| FWIW | For What It's Worth | |
| FYA | For Your Amusement | |
| FYI | For Your Information | |
| (-: to the Emoticons :-) |
