(2) Transfer of applications and registrations shall be in writing and signed by the contracting parties. (3) Assignment for transfer of registered industrial designs by inheritance shall be recorded in the Industrial Designs Office after payment of the fees prescribed by the rules, and assignment and transfer of applications shall be registered previously after payment of the fees. After registration of an industrial design it shall be registered in the name of the assignee or beneficiary. (4) The assignment or transfer shall not be effective against third parties unless recorded in the register. 28. In the absence of any agreement to the contrary between the contracting parties, any or the owners participating in a registered industrial design may assign his share or benefit in the industrial design and exercise the rights conferred by section 25, provided that there shall be no license to third parties to utilize the industrial design without their unanimous consent. Part Nine: Licenses 29. (1) The owner of an industrial design may grant by contract or by undertaking to another person a license to utilize an industrial design. (2) The license shall be in writing and signed by the contracting parties. (3) The license or an appropriate summary thereof shall be registered in the Industrial Designs Office after payment of the fees stipulated by the rules. The license shall not be effective against third parties unless registered. (4) Registration of a license shall be cancelled on the application of the registered owner of the industrial design after proving the expiry of the license. 30. (1) The conditions set out in a license or connected thereto shall be void if they impose on the license in the industrial or commercial field restrictions not derived from the rights granted by registration of the industrial design or not necessary for the protection of those rights. (2) The following special cases are not regarded as restrictions: (a) restrictions concerning the extent of the use of an industrial design or its scope or the term or method or amount of production for which an industrial design may be used;