Choose your mode:

DON'T CUT ALONG CUT FRAME

Select the part to modify then the frame defining the plane which will not have to be divisible.

The part won't be cut in the TopSolid/Draft document if the selected cut plane is the same as the plane defined by the frame (example: woodruf key)

DON'T CUT ALONG CUT AXIS

Select the part to modify then click an axis.

The part won't be cut in the TopSolid/Draft document if the selected plane contain the axis (example: a screw)

NEVER CUT

The part will never be cut.

If there is only one projected part on the TopSolid/Draft document, the divisible property will not be effective because in this case you voluntarily want to cut this part.