I was once on a job that the specs called for 3/4” plywood. It was not my trade, but the carpenter used “3/4” “ plywood that is, in reality, about 1/16” thinner than that. The douchebag building inspector made them remove the offending plywood and replace it with special-order-shipped-from-the-Pacific-Northwest-honest-to-God 3/4” plywood at great expense to the contractor. Calling the inspector an idiot would be charitable.
I’ve discovered the plywood discrepancy before...when I tried replacing lart of a floor and couldn’t find anything that matched the old floor.