46 CFR 502.115: Service in rulemaking and petition proceedings.

Service on all prior participants in a rulemaking or a petition proceeding must be shown when submitting comments or replies beyond the initial round, including those involving disposition of petitions for rulemaking (Rule 51), petitions for declaratory order (Rule 75), petitions general (Rule 76), notices of proposed rulemaking (Rule 52), proceedings under section 19 of the Merchant Marine Act, 1920, (46 U.S.C. 42101) (Part 550), and proceedings under section 13(b)(6) of the Shipping Act of 1984 (46 U. S.C. 41108(d)) (Part 560). A list of all participants may be obtained from the Secretary of the Commission.