This document provides information about the Harmonized Commodity Description and Coding System (Harmonized System or HS) and the ASEAN Harmonized Tariff Nomenclature (AHTN). It discusses the origin and development of the HS, its composition and uses. It also explains what the AHTN is, its relationship to the HS, and its advantages. Finally, it outlines the General Interpretative Rules that provide principles for classification under the HS nomenclature.