All the ways companies have of obfuscating nutritional information for no obvious reason.
A 500 grams yogurt container will be labeled with how many calories/protein/etc it has per 75 grams. The one next to it will also have a label with that information... but it's per 125 grams. So you can't even compare them to each other. Would it be too much to list the macros for the whole thing?
Bagged salad kits will tell you the macros including the dressing (which is inside each bag but in a sealed, separate container). Would it be too much to list that separately?
That's without even accounting for marketing or legal tricks such as advertising as 'low-carb' or 'light' products which are more sugar-packed than the average candy bar. And don't get me started on 'natural'.
<grumblegrumble>