A portion of the POnSrf help is about “Percentage” option from the POnCrv help and not relevant to POnSrf. It needs to be deleted. See bolded italic below.
PersistentOnSurface (POnSrf)
Snap to and track over a surface until the command completes.
To access this object snap on the Osnap control
- Press and hold the Ctrl key and hover the mouse over the Osnap control.
### Percentage (Percent)
The selected curve is marked with temporary black points that can be snapped when the Point object snap is disabled.
If the percentage is less than 50, the curve is marked with multiple snap points. For example, when using 30, you get snap points at 30%, 60% and 90%.
To access this object snap on the Osnap control
- Press and hold the Shift key and hover the mouse over the Osnap control.