[ImperialCrown]

Moving the switch up causes an upshift and moving the switch down causes a downshift. The instrument cluster will illuminate the selected gear. The vehicle can be launched in 1st, 2nd, or 3rd gear while in the Autostick mode. The speed control is operable in 3rd and 4th gear Autostick mode. Speed control will be deactivated if the transaxle is shifted to 2nd gear. Shifting into OD position cancels the Autostick mode, and the transaxle resumes the OD shift schedule.

 

[ImperialCrown]

Very rare and I personally can't see any real advantage to having auto-stick other than the occasional boy-racer feel. It is easy enough to manually select which gear range you desire with the shift lever.

 

[ImperialCrown]

The knob ring twists CW or CCW to step up or down ratios. Auto-Stick appears as A/S in the shifter display. The sliding button locks or unlocks the knob ring for A/S twisting.
It should be covered in the owners manual.