From the Urban Dictionary:
Feldercarb
An expletive used by the characters of Battlestar Galactica that refers to the putrid and crusty black grime that would accumulate on various pieces of machinery and required scraping off during maintenance. Possibly Battlestar-speak for bs."
I still say "frack" and "feldercarb".
Loved the original BG.
Nice to have some background on that. :P