All of the imports and export codes used by the United States are based on the international Harmonized System (HS). The HS assigns 6-digit codes for general categories. Countries which use the Harmonized Tariff Schedule (HTS) are allowed to define commodities at a more detailed level than 6-digits, but all definitions must be within that 6-digit framework. The U.S. defines products using 10-digit HTS codes. Exports codes (which the U.S. calls Schedule B) are administered by the U.S. Census Bureau. Import codes (called HTSA) are administered by the U.S. International Trade Commission (USITC).
Translating a HS code into its corresponding SITC & NAICS codes or NAICS & SITC codes into HS codes.
Correspondence between NAICS and SIC codes.
For more international economic and social classification systems, see the UN's Statistical Classifications.
Articles and Working Papers (from the general economics guide)
Many U.S. agencies are involved in the formulation of trade policy. All fall under the coordination of the Office of the United States Trade Representative. The USTR Web site covers agreements, preference programs, policies on industry sectors, and more. Of particular interest:
U.S. International Trade Commission
The Commission "provides trade expertise to both the legislative and executive branches of government, determines the impact of imports on U.S. industries, and directs actions against certain unfair trade practices, such as patent, trademark, and copyright infringement."
Foreign Agricultural Service, USDA
Agricultural trade policy.
