46 CFR 163.003-25: -25 Marking.

(a) Each pilot ladder step manufactured under Coast Guard approval must be branded or otherwise permanently and legibly marked on the bottom with—

(1) The name of the manufacturer;

(2) The manufacturer's brand or model designation;

(3) The lot number or date of manufacture; and

(4) The Coast Guard approval number.

(b) In addition to the markings required under paragraph (a) of this section each step sold as a replacement step must be branded or otherwise permanently and legibly marked with the words “REPLACEMENT STEP ONLY.”