council decis decemb accept custom cooper council recommend june amend articl xiv xvi convent nomenclatur classif good custom tariff eec council european commun regard treati establish european econom commun articl thereof regard recommend commiss member state contract parti brussel convent decemb nomenclatur classif good custom tariff common custom tariff base nomenclatur custom cooper council recommend amend convent contract parti june recommend amend articl xiv xvi convent convent belgian ministri foreign affair commun draft text recommend amend contract parti govern signatori acced state text deem accept object notifi contract parti month date commun object notifi amend enter forc month expiri period belgian ministri foreign affair commun text recommend june contract parti june effect juli object notifi part text recommend deem accept decemb enter forc juli object made part recommend decid sole articl custom cooper council recommend june amend articl xiv xvi convent nomenclatur classif good custom tariff accept applic juli brussel decemb council presid genscher