"Red heads" are, strictly speaking, outside the range of this thread. After all, there's no rule AGAINST using them.

By contrast, let's look at this clip made by Caddy:
http://www.erico.com/category.asp?category=R1106

This fitting is one of many that are designed specifically to attach conduit and boxes to suspended ceiling grids. I've seen installations that used these clips, so it's possible that they were allowed at some time.

Today, though, I can see no situation where the NEC allows anything to be supported by any suspended ceiling.

I don't buy the "for positioning only" disclaimer.

What about the lack of a UL listing? As best I can tell, supports are not required to be listed. Caddy lists its' "minerallac" style hanger, but not the one-hole straps. As best I can see, code allows you to hang pipe using rubber bands, shoe laces, and bubble-gum ... as long as you're not hanging it from the ceiling grid!

IS there any 'legal' use for these t-bar fittings?