this is how the 5-way rotary uses the pickups on my PRS acording to the PRS website:

Position 10: Treble pickup
Position 9: Outside coils- deep and clear - parallel
Position 8: Series single coils – Warm version of the "in between the treble and middle pickups"
Position 7: Series single coils-warm version of the "in between the treble and middle pickups"
Position 6: Bass pickup

it goes from 10-6 because it's the same 1-10 knob used for tone and volume. It's basically the exact same thing as a 5-way toggle switch like what's on a strat, etc... I'm planning on having it switched out for a 3-way toggle switch and have the tone knob changed to a push-pull pot that will make it go from humbuckers to single coils.