The main principles of GATT 19 47 were as follows: (1) Trade 1 was forbidden . Each contracting state had to 2 the same trading privileges and benefits (or most- 3 -nation status) to all other contracting states equally; and, once foreign trade goods were imported into one contracting state from another, the foreign goods had to be treated (according to the national 4 principle) the same way as domestic goods . (2) With some exceptions, the only 5 that one contracting state could use to limit the importation of goods from another contracting state were customs tariffs . ( 3 ) The trade regulations of contracting states had to be 6 , that is, published and available to other contracting states and their nationals . ( 4 ) Customs 7 and free trade agreements between contracting states were regarded as legitimate means for liberalizing trade so long as they did not, on the whole, discriminate 8 third-party states that were also parties to GATT . (5) GATT-contracting states were allowed to levy only certain charges on imported goods: (a) an import tax equal in amount to internal taxes, (b) 9 duties to offset advantages obtained by imported goods that were sold below the price charged in their home market or below their actual cost, (c) countervailing duties to counteract foreign export 10 , and (d) fees and other proper charges for services rendered .