I don't have RFB but when I select an aircraft, the description of the aircraft usually tells me what the various switches are used for on the aircraft. Over time it has become somewhat standard.
Airplanes:
Channel 8 triple switch - sometimes smoke, sometimes aircraft doors. Not really a standard for this switch.
Channel 5 up is high rates, down is low rates (large control surface movement on high rate)
Channel 7 is usually on/off for smoke or landing gear.
Channel 6 dial usually operates the planes flaps.
Helicopters
Channel 8 triple switch - away is normal, up is for idle up (Positive & Negative Pitch-3D maneuvers, beginners use normal for hover.)
Channel 5 up is high rates, down is low rates (same as planes, more sensitive on high rates... beginners use low rates)
Channel 7 is usually Throttle hold Up-on-active throttle, down-off-zero head rotation.
Channel 6 dial usually not used. They say gain, like increasing the heli gyro gain, but I have not seen this used this way.
Each aircraft designer can change what a control does on the aircraft so this is in general only.