In the USA (in Live ATC and in VATSIM ATC) I've heard hand off to ground as"contact ground on point 8" (e.g. KSFO). I used to think that was just short cut to saying "you ought to know the frequency, it's the one ending .8" but now I'm thinking it's a universal short cut for 121 point something (and always ground?)

I've searched around and can't find anything on this. Could anybody from that side of the pond shed some light on this practice please?

Many thanks,
Gez