46 C.F.R. § 162.028-4
Marine type label
(a) In addition to all other markings, every portable extinguisher must bear a label containing the Coast Guard approval number, thus: “Marine Type USCG Type Approval No. 162.028/____.”
(b) All such labels are to be obtained only from the recognized laboratory and will remain under its control until attached to product found acceptable under its inspection and labeling program.