It's just in their rules.
Depth is always "hip crease below top of knee" or some wording to that effect in every federation..
but there are some American Equipped feds where the judging is a real joke.
people getting green lights for squats that are like 2 inches above parallel.
GPC, CAPO considers knee wraps to be RAW powerlifting.
in PA, knee wraps are only used for Equipped lifting.
but they allow knee sleeves... which don't really add anything to your lift..
but like with all rules, people bend them...
the rule around knee sleeves were changed in IPF (PA) after this..
basically using a sleeve that would be really tight around an elbow, on your knees.
They were using a plastic bag to help get it up to the knee.
lol