Introduction: The law
The current legal basis for each trading Agreement between the EU and those countries that grant preferential treatment to goods that originate in the Community is contained in various EC regulations. They only relate to trade between the EU and the state(s) concerned. Most of these are reciprocal (2-way), but some are autonomous (imports into the EU only).
The regulations provide for the administration of the regime and lay down the rules of origin.
An up-to-date list can be found in Volume 1, part 7 of the UK Tariff. The Tariff is now available online at http://businesslink.gov.uk/bdotg/action/tariff?r.s.=a