Nomenclature is the term used to describe the systematic naming of things. The Harmonized System (HS) is an international goods nomenclature consisting of General Rules of Interpretation (GRI's),
Section and Chapter legal notes, and the 4-digit Heading and 6-digit Subheading numerical codes.
Each World Trade Organization (WTO) member country has agreed to utilized the foundational international Harmonized System nomenclature, however, duty rates are not harmonized and are established country by country or through multilateral agreements.
The United States has augmented the international nomenclature, referring to it as the Harmonized Tariff System of the United States (HTSUS, or HTS for short), assigning U.S. import duty rates and making trade agreements with trading partners worldwide that can confer preferential import rates.
An additional U.S. General Rule of Interpretation with four parts was also added, as well as national-level notes for each Section and Chapter to specifically administer classification of commodities as ruled in the United States.
Finally, special duty provisions were added as additional chapters in the systems (Chapter 98 and 99), along with reference material at the end of the tariff.
The "Harmonized System of Tariff Classification and Statistical Coding" contains a considerable amount of information. However, because it is very systematically laid out, it is not difficult to understand, navigate and apply.
The following provides an explanation of each major area of the Tariff, covering the type of information, how it is structured, and how it can best be interpreted and used. There is also a discussion of the specialized language that is used throughout the Tariff.