Modifying the rates of import duty on certain imported articles as provided under the Tariff and Customs Code of 1978, as amended, in order to implement the decisions of the Eighteenteenth ASEAN Economic Ministers (AEM) and twenty-first Committee on Trade and Tourism (COTT) meetings to provide a minimum level of 25% margin of preference in respect to items which are under the ASEAN preferential trading arrangements (PTA)