49 CFR §179.500-17

1. (a)Each tank shall be plainly and permanently marked, thus certifying that tank complies with all requirements of this specification. These marks shall be stamped into the metal of necked-down section of tank at marked end, in letters and figures at least 1/4 inch high, as follows:
   1. (1)Spec. DOT-107A * * * *, the * * * * to be replaced by figures indicating marked test pressure of the tank. This pressure shall not exceed the calculated maximum marked test pressure permitted, as determined by the formula in § 179.500-4(b).
   2. (2)Serial number immediately below the stamped mark specified in paragraph (a)(1) of this section.
   3. (3)Inspector's official mark immediately below the stamped mark specified in paragraph (a)(1) of this section.
   4. (4)Name, mark (other than trademark), or initials of company or person for whose use tank is being made, which shall be recorded with the Bureau of Explosives.
   5. (5)Date (such as 1-01, for January 2001) of tank test, so placed that dates of subsequent tests may easily be added.
   6. (6)Date (such as 1-01, for January 2001) of latest test of pressure relief device or of the rupture disc, required only when tank is used for transportation of flammable gases.
2. (b)[Reserved]