Artikel 12

1. Modifications of this Convention, which may be deemed useful or necessary, and of the annexed Regulations, may, at any time be proposed by any Contracting Government to the Government of Norway, and such proposals shall be communicated by the latter to all the other contracting Governments, and, if any such modification are accepted by all the Contracting Governments (including Governments which have deposited ratifications or accessions which have not yet become effective) this Convention and/or the Regulations shall be modified accordingly.
2. Conferences for the purpose of such revision shall be held at such times and places as may be agreed upon by the Contracting Governments.
Conference for this purpose shall be convened by the Government of Norway, whenever five or one third, whichever is the lesser, of the Contracting Governments express a desire to that effect.