In my view, however, they (in their form of the super genera Quantity, Quality, etc.) are not a priori determinations (categories in Kant's sense), but general principles of Being (namely principles of Being with respect to phenotypic expression).
If we consider, for example some definite quality, that we observe with respect to a given individual being, and generalize it maximally, we arrive at Quality (as highest genus), and this is then one of the general principles of Being.