In 2266, Harcourt Fenton Mudd used subspace frequency three-nine to contact Rigel XII with a communicator aboard the USS Enterprise. (TOS: "Mudd's Women" ) In the final draft script of "Mudd's Women", this frequency was instead called "sub-space B three nine". The next year, Captain James T. Kirk asked Lieutenant Uhura to contact a private transmitter designated GSK-783 on subspace frequency three. (TOS: "Operation -- Annihilate!" )