The "F" word substitute for the TV series Farscape. Using "Frelling" allowed the characters to swear at will making it seem natural.
Farscape (1999–2003) is a science fiction television series, featuring a present-day astronaut who accidentally travels through a wormhole to a distant galaxy on the other side of the Universe.
Example - Your favourite coat has just been ruined by a stray shot from a pulse pistol. "Frell! You've destroyed my frelling favourite coat you frelling piece of dren (qv)"