I never knew snakes needed oiling.
I think DC meant "Velocity Factor".
"Velocity of Propagation (VoP) or velocity factor is a parameter that characterizes the speed at which an electrical signal (e.g. radio or audio) passes through a medium. Expressed as a percentage, it is the ratio of a signal's transmission speed compared to the speed of light in vacuum or the speed of sound. Thus, transmission in a vacuum would have a VoP of 100. VoP equals the reciprocal of the square root of the dielectric constant of the material through which that signal passes."