States basic technical requirements for cathode heating of tubular fluorescent lamps having pre-heated cathodes and intended for use in starterless circuits at a frequency of 50 Hz or 60 Hz. The requirements presented are those needed, as far as cathode heating conditions are concerned, to obtain reliable lamp performance. Ballasts used for the operation of these lamps should supply cathode heating voltages and currents in accordance with these basic requirements. This publication has the status of a report.