A/RES/59/38 or industrial property which enjoys a measure of legal protection, even if provisional, in the State of the forum; or (b) an alleged infringement by the State, in the territory of the State of the forum, of a right of the nature mentioned in subparagraph (a) which belongs to a third person and is protected in the State of the forum. Article 15 Participation in companies or other collective bodies 1. A State cannot invoke immunity from jurisdiction before a court of another State which is otherwise competent in a proceeding which relates to its participation in a company or other collective body, whether incorporated or unincorporated, being a proceeding concerning the relationship between the State and the body or the other participants therein, provided that the body: (a) has participants other than States or international organizations; and (b) is incorporated or constituted under the law of the State of the forum or has its seat or principal place of business in that State. 2. A State can, however, invoke immunity from jurisdiction in such a proceeding if the States concerned have so agreed or if the parties to the dispute have so provided by an agreement in writing or if the instrument establishing or regulating the body in question contains provisions to that effect. Article 16 Ships owned or operated by a State 1. Unless otherwise agreed between the States concerned, a State which owns or operates a ship cannot invoke immunity from jurisdiction before a court of another State which is otherwise competent in a proceeding which relates to the operation of that ship if, at the time the cause of action arose, the ship was used for other than government non-commercial purposes. 2. Paragraph 1 does not apply to warships, or naval auxiliaries, nor does it apply to other vessels owned or operated by a State and used, for the time being, only on government non-commercial service. 3. Unless otherwise agreed between the States concerned, a State cannot invoke immunity from jurisdiction before a court of another State which is otherwise competent in a proceeding which relates to the carriage of cargo on board a ship owned or operated by that State if, at the time the cause of action arose, the ship was used for other than government non-commercial purposes. 4. Paragraph 3 does not apply to any cargo carried on board the ships referred to in paragraph 2, nor does it apply to any cargo owned by a State and used or intended for use exclusively for government non-commercial purposes. 5. States may plead all measures of defence, prescription and limitation of liability which are available to private ships and cargoes and their owners. 6. If in a proceeding there arises a question relating to the government and noncommercial character of a ship owned or operated by a State or cargo owned by a State, a certificate signed by a diplomatic representative or other competent authority of that State and communicated to the court shall serve as evidence of the character of that ship or cargo. 8