You can, but you'll still have another orange squiggle on the line. It will still say that the callback function might not be used. Duh! It's a callback, and won't get used unless someone interacts with the control it's associated with. You can suppress warnings, but I didn't suppress that warning because what if there is some dead code function somewhere in your code that you custom wrote (not a built-in callback generated from GUIDE)? I'd like to know about those unused functions. However I have so many of these callbacks that my right margin is just a virtual barcode of orange and gray stripes, so I tend to ignore them on the margin.
If it's in the code window (text editor) and it's a valid suggestion, then I will take corrective action, but I ignore most on the right panel because there are simply too many.
