Commission Regulation (EEC) No 3512/80 of 23 December 1980 derogating in respect of the countries of the Central American Common Market from Articles 1, 6 and 12 of Commission Regulation (EEC) No 3510/80 of 23 December 1980 on the definition of the concept of originating products for purposes of the application of tariff preferences granted by the European Economic Community in respect of certain products from developing countries