HS (Harmonized System): nomenclature of the World Customs Organization, shared by more than 200 countries. The HS code has 6 digits: 2 for the chapter, 4 for the heading, 6 for the subheading. Example: 6109 10 covers T-shirts and singlets, knitted or crocheted, of cotton.
CN (Combined Nomenclature): the European Union's nomenclature, with 8 digits. It adds 2 digits to the HS code and is published every year in the Official Journal of the EU.
TARIC: the EU's integrated tariff, with 10 digits. It brings together all the measures linked to a code: duties, quotas, suspensions, prohibitions.
HTS / HTSUS: the United States nomenclature, with 10 digits, published by the USITC. Example: a men's cotton T-shirt falls under 6109.10.00, with a statistical suffix depending on the product.
UK Global Tariff: the United Kingdom's nomenclature, with 10 digits, available on GOV.UK's Trade Tariff.
GIR (General Interpretative Rules): six rules that set the classification method. Rule 1 gives priority to the terms of the headings and to the notes. Rule 6 applies the same logic to subheadings.
Section and chapter notes: legal texts at the start of each section and each chapter. They include or exclude goods and have the same force as the terms of the headings.
HSEN (Harmonized System Explanatory Notes): official WCO commentaries that clarify the scope of headings. Example: they distinguish a jacket from a blouson by its fastening and length.
Final (terminal) code: the last level of the nomenclature, the one declared to customs.
EORI: identification number of economic operators with EU customs, mandatory to import or export.
Origin: the country where the goods were obtained or underwent their last substantial transformation. Non-preferential origin is distinct from preferential origin, which derives from a trade agreement and requires proof.
REX: the EU's registered exporters system, used to attest preferential origin under certain agreements.
See also: How to find a product's customs code, Help Center.