Sounds like they expect it to be suspended from a hook in a beam or the ceiling. Without seeing an example close up it is difficult to say, but I am thinking in terms of a wooden frame attached to the back at multiple points, with a female threaded adaptor screwed onto the bottom bearer. I have seen basic ones which are little more than a steel plate with a couple of screw holes with an appropriate threaded nut welded on (on tripod size). We bought some for a a restsurant job a few years back. I'll see if I can find the brand, etc