तयोः पादावरो विधाविधिः ॥ कZ_०२.३१.१२ ॥
tayoḥ pādāvaro vidhāvidhiḥ
For those two (i.e., the higher grades), the rule is that they should not be deficient by even a quarter (in the prescribed standards).
It sets a measurable tolerance: top grades must meet the standard closely and cannot fall short by a defined fraction.
To reduce disputes, corruption, and inconsistent acceptance decisions by inspectors.