Abstract: A signal substitution system for cable television applies substitute television program signals in at least one substitute channel to the transmission cable along with signal substitution control signals. The signal substitution control signals include a plurality of different terminal command signals and a plurality of different event command signals. Each of the terminal command signals includes a respective panelist address signal for identifying a respective panelist receiving station and a plurality of event identification signals identifying respective events. Each of the event command signals includes a respective event address signal corresponding to a respective event and a normal channel identification signal for identifying a normal channel into which a substitute television program is to be switched. A controller at each panelist receiving station responds to the signal substitution control signals by selectively switching a substitute television program into a normal channel.