Artikel 4

1. Countries members of the Economic Commission for Europe and countries admitted to the Commission in a consultative capacity under paragraph 8 of the Commission's Terms of Reference, may become Contracting Parties to this Convention:
(a) By signing it;
(b) By ratifying it after signing it subject to ratification;
(c) By acceding to it.
2. Such countries as may participate in certain activities of the Economic Commission for Europe in accordance with paragraph 11 of the Commission's Terms of Reference may become Contracting Parties to this Convention by acceding thereto after its entry into force.
3. The Convention shall be open for signature until 18 May 1957, inclusive. Thereafter, it shall be open for accession.
4. Ratification or accession shall be effected by the deposit of an instrument with the Secretary-General of the United Nations.