Wire Shelving Clips

We use NSF wire shelving in our kitchen, because our apartment doesn't have a pantry. We also hang our kitchen tools and cast iron pans off the shelving with hooks, to maintain 1st-order accessibility, and save limited drawer and shelf space. 

The standard s-hooks for wire NSF shelving have some design flaws- they slide and pivot while you are hanging something on them, and when taking something off you have to be careful not to to take the hook off the shelf as well (and find wherever it bounced to on the floor). There's a few 3-d printed solutions to this, but none of them will hold up to a 8" cast iron skillet. 

So, there is a need for something to hold these hooks in place.

Strategy

Starting with requirements: Something that clips over the top of the hook, holding it to the edge of the shelf. Should be removeable, not permanently attached to the hook, easy to apply and remove, but not likely to be unclipped by accident. Should be made from a single FDM print with as little support material as possible. One size must function across the manufacturing tolerances of the hooks and racks.