International Convention for the Prevention of Pollution from Ships, 1973

Article 13

Signature, ratification, acceptance, approval and accession

(1) The present Convention shall remain open for signature at the Headquarters of the Organization from 15 January 1974 until 31 December 1974 and shall thereafter remain open for accession. States may become Parties to the present Convention by:
  (a) signature without reservation as to ratification, acceptance or approval; or
  (b) signature subject to ratification, acceptance or approval, followed by ratification, acceptance or approval; or
  (c) accession.
(2) Ratification, acceptance, approval or accession shall be effected by the deposit of an instrument to that effect with the Secretary-General of the Organization.
(3) The Secretary-General of the Organization shall inform all States which have signed the present Convention or acceded to it of any signature or of the deposit of any new instrument of ratification, acceptance, approval or accession and the date of its deposit.