any pre-set value or quantity, authorized for importation or exportation of given goods, during a specified period, with a reduction of the normal Customs duties, and beyond which the granting of the said tariff reduction may be suspended until the end of the period in question, tollitariifi lagi - kaubakogus, mille ületamisel võib Vabariigi Valitsuse korraldusega peatada kauba importimise või eksportimise soodsama tollitariifi määraga