(a) Timber sale contracts may provide for volume determination by scaling, measuring, weighing, or counting the logs or other products, or by measuring the trees before cutting. If the contract or permit provides for the determination of volume by tree measurement and the timber has been paid for, the marking or otherwise designating of the tree authorizes cutting and removal. Otherwise no timber cut under any contract shall be removed from the place designated until it has been scaled, measured or counted as provided in the timber sale contract, unless such removal is specifically authorized in the contract.

(b) National Forest timber sold on board foot scale shall be scaled by the Scribner Decimal C Log Rule, or if the advertisement and contract or permit so state, by the International 1⁄4 -inch log rule or by the International 1⁄4 -inch Decimal log rule. National Forest timber may also be sold by the cubic volume rule or by cords, each as used by the Forest Service.