It is an abreviation for Rythem Move and Beat. Like pop and rock music.

Stands for: Red Mystery Box, in the PlayFish Game, PET SOCIETY.

It's worth 50 coins, and is commonly used in various trading forums, for buying the cheapest items.

Race Me Back

(A reference to the popular iphone game, "Bike Race", where friends can race each other online.)

simply mean rub my booty