What are all of the pedals for on an organ?

What are all of the pedals for on an organ?
The pedal keyboard is simply another keyboard, played with the feet.
There are also expression pedals. These are the large flat pedals mounted on the "kick panel." One type is used to control the volume of the "expressive divisions" by opening and closing the expression shades. Another type of expression pedal is the register crescendo which brings on stops incrementally. It is used for special effects and should not be used as a registration device. Although not technically pedals, there are also toe studs or toe pistons. These, and other controls, are used to control the combination action and often on large organs are used to directly control important stops. Older organs will often have lever-like devices ("Spoons") that controlled primitive primitive combination actions, to actuate the blowing apparatus and / or control "ventils" to turn off and on groups of stops pre-set by the organist.