It's the "F" in the common web acronym "FAQ"
The following list highlights some of the most commonly used acronyms 
on chat sites, instant ... F2F: Face to face; f: Female; fb: Facebook; FUBAR: 
Fouled up beyond all recognition; FWIW: For what it's worth; FYI: For your 
information... [DOC] [TLE] The 75 Most Important Social Media Acronyms | Sprout Social [PAR] Jun 17, 2015 ...