I have been using Metro Shelving Carts for decades. I have always wished for a proper hook to attach to the shelves to hand light stands, lighting, cables, cameras to open up more space.
This snaps into the front bottom rail of the shelf, then you move it into position to click into the 2nd wire on the shelf.
I made it intended to clip from the back side of the shelf so you can hang things up against a wall.
I have a couple other renditions for other applications on the shelving that I will post in the next few weeks.
https://metro.com/wire-shelving/
https://metro.com/shop/metro-super-erecta-industrial-wire-shelf-chrome/
The author marked this model as their own original creation.