Kicad, make a rectangular board cutout through the entire board

Okay, I've spent way too much time on this and maybe it's not possible. I am making a PWB using Kicad and cannot for the life of me make a rectangular cutout through the interior of the entire board. I can make keep-out zones and they don't get copper in them, but there is board material in them. Has anyone done this using Kicad? Thanks.

Well, I finally found out how to do it. Select the edge cut layer on the right side panel. Draw a graphic polygon defining the cutout. Viola! Easy once you figure out how to do it. I guess not many active Kicad users here.

I use Kicad regularly but never had quite the need for it.
There is also the official KiCad forum where I believe one of the developers moderates.
Max.