I agree with Karldotcom. I have the Burbank Cell as System #1, Glendale Cell as System #2, etc. I program each system with many of the same groups, i.e. Burbank PD, Group #1, Glendale PD Group #2, Verdugo Fire, Group #3, etc. I keep the other Burbank frequencies for Water and Power, services etc. just on the Burbank System and the other Glendale Service Groups on only the Glendale System.
While the BCD396T only needs the Control channels to operate the System, I input ALL the frequencies assigned to the Cell as I never know when they may make another frequency a control channel and it isn't like adding the extra frequencies is going to degrade the memory of the scanner.