spindle.N.on missing from docs

I see that spindle.N.on is referenced in many examples on the net but also in the spindle documentation of linuxcnc:

linuxcnc.org/docs/html/examples/spindle.html

But it seems like missing from the man page. How could that be? 
I have the impressions the the pins are autogenrated from the .comp file (or something similar)

linuxcnc.org/docs/html/man/man9/spindle.9.html

NOTE: This component is unfortunately named and creates pins with names very much like those created by the motion component.
In nearly every case this is not the documentation page that you are looking for.
See linuxcnc.org/docs/html/man/man9/motion.9.html instead.

The pin you are referring to is in the motion component.