Basic Principles of the GATT:

The basic principles  of the GATT are most favoured  nation (MFN)  and  national treatment (NT).  MFN means that if a country gives a concession to another country,  it has to extend the concession to all counties with whom it has  an MFN  agreement.  So MFN  implies that  all foreign suppliers are treated equally. NT means that once an imported good crosses the boundary and has paid  the border charges it is accorded the same treatment as domestically  treated goods. This regulates competition between the  imported  good  and  the domestic good.  The two  together  provide certainty to  foreign exporters about the competition they will  face  in  the domestic market.

The negotiations for reduction of duties are conducted under the principle of reciprocity.  A country in the negotiations is expected to give concessions on imports equivalent to concessions it receives on its exports. Also to provide certainty that tariffs would not be  increased in  the  future, tariff rates were bound.  Tariff rates could be below the binding but  not  above it.  So,  the negotiations are about the rate at which tariffs would be bound, not the actual rate.

A series of multilateral trade negotiations (MTNs) were undertaken under the aegis of GAn  to  reduce  trade restrictions. GATT negotiations were  restricted to manufactures. 

At  US  insistence,  agriculture was  kept  out of  the negotiations. Trade  in  textiles was also governed  by the multi-fibre agreement (MFA). Under this agreement each developed country established quotas for the import of different textile items from each developing country.