20. According to the «T-Boat» regulations, what is the name given to the permanent marks placed on each side of a vessel forward, aft, and amidships to indicate the maximum allowable draft and trim?

Loading marks are the regulatory term for permanent draft and trim markings on T-boats, indicating the maximum allowable draft and trim at forward, aft, and amidships locations as defined in 46 CFR Subchapter T.