Customs duty exemption for imported components used in manufacture for the public telephone exchange project reduces payable ad valorem and additional duty. Exemption applies to imports of components and raw materials under the relevant tariff heading when brought in for manufacture of instruments and equipment for the Public Telephone Exchange Network Project: the portion of ad valorem customs duty in excess of a 35% cap is exempted, and the whole of the additional customs duty otherwise leviable is also exempted; the project is defined by reference to a prior government notification.