Ƒ

The letter Ƒ (minuscule: ƒ) is a letter of the Latin alphabet, based on the italic form of F. It is used in writing the Ewe language to represent a voiceless bilabial fricative (IPA: /ɸ/), as distinct from the letter F, which represents a voiceless labiodental fricative. Compare

Ƒ Media

Lowercase F with a hook in regular type on the left and in italic on the right, the florin sign is always in italic.
The non italic f with hook used for the florin sign on the price chart for the Algemeen Dagblad in 1980.

Ʋ, which is the equivalent voiced sound.

The minuscule ƒ is also used as an abbreviation for florin, gulden and guilder.

The lowercase ƒ is also used in mathamatics for funtion notation:

ƒ(x)=πx²

Older fonts and character encodings included only the minuscule form for its use as an abbreviation. Unicode includes both the majuscule and the minuscule.