Where in the code does it say that recepticals can not face up. We are putting in some 4000 wiremold with power to feed some desks. The carpenters want us to put the wiremold faceing up behind the desks mounted on a window seal. The wall under the window is furred out about 16 inches. They want us to do this because there will be no access to the wiremold if we mount in on the wall insted of above the wall.