I created a slab and then trimmed it by two surfaces on either side of the x axis.

I then translated/dragged a copy off to the model's left an changed it to a surface. That edit warned/advised me that there were dependencies. I accepted.

The result: the two side surfaces had a "teleported" twin of themselves, but with all control points turned on with the two surfaces appearing as if in wire frame mode.

This same result occured when I changed the original, non-translated slab, but applied its effects to the parent side surfaces.

I discvered this when trying to figure out why my slabs are not "associative" to the surfaces that cut them. Moving the splines that control the shaping of the surfaces has no effect on the outward shapes of the slabs that somehow are associated to the outer surfaces.

Also, these outer surfaces to not appear in the Feature Tree when a translation-copied part is dragged off to the side and examined in the Feature Tree tab. Of no surfaces are related by visual inspection of the Feature Tree, then why is there a phantom or teleported pair of cutting surfaces that appear and are not selectable?

Also, while a slab or surface in the drawing can be zoomed in on seemingly to infinity, zooming in on the "teleported" control points of the phantom vanish when zoomed in to a certain point.