bit char g 4 band multi controller

there is a 3 way switch on the back of my 4 band controller that is labelled "C B A".

it appears to select between different "channels" on each of the 4 different frequencies, as each of my cars will only operate on a certain frequency with this 3 way switch set in one of the positions.

does anyone know exactly what this does?

does this mean that there are multiple channels on each frequency?

will we someday be able to race several cars on one frequency(or can we now)?

--t