"flipflop", "float", "form", "function"
Mostly harmless, but there is a smattering of extra uses.
Operators containing this character
ff and fff create flipflop ranges
When used inside regexes
\f is a form feed character, the same as in interpolated strings
As an adverb
:f applied to a generalized quote interpolates and calls
%f in a printf format outputs a number in floating point format
\f in interpolated strings represents a form feed