It's interesting that this is legally required - I was not aware! I went to my pantry and looked at labels and I do see sugar listed there.
If I were a manufacturer, I would just reduce the serving size to get past the necessity of showing sugar contained in the product.
My habit is just to look for added sugar. There have been numerous articles in the press over the years about how to detect added sugar. The American Diabetes Association does a good job explaining sugar and nutrition labels. I'm not diabetic.