Taper Factor: Controls the amount that selected points are tapered (as a percentage) along the current Active Axis. Use the ControlChannel to control how the taper amplitude is distributed along the Active Axis.
Displace X, Y, Z: Controls which of the selected points coordinates will be scaled to create the Taper effect.
OK: Closes the tool, with alterations intact..
Cancel: Closes the tool, canceling any alterations.
Set: Makes any alterations permanent, and leaves the tool open, ready for further use.
The Taper tool also includes a standard Origin Tab, allowing you to set the Origin point around which points are tapered.