-18 Stamping.

(a)To certify that the tank complies with all specification requirements, each tank shall be plainly and permanently stamped in letters and figures 3/8 inch high into the metal of valve end chime as follows:#

(1)DOT Specification number.#

(2)Material and cladding material if any (immediately below the specification number).#

(3)Owner's or builder's identifying symbol and serial number (immediately below the material identification). The symbol shall be registered with the Bureau of Explosives, duplications are not authorized.#

(4)Inspector's official mark (immediately below the owner's or builder's symbol).#

(5)Date of original tank test (month and year, such as 1-64 for January 1964). This should be so placed that dates of subsequent tests may easily be added thereto.#

(6)Water capacity—0000 pounds.#

(b)A copy of the above stamping in letters and figures of the prescribed size stamped on a brass plate secured to one of the tank heads is authorized.#