Combined nomenclatures are a list of descriptions of goods, based on the harmonised system, enabling the common customs tariff to be applied, external trade statistics to be established and for other EU policies to be taken into account. European Union-level system for the description and codification of goods.

The CN is composed of 8 characters:

♦ The first 6 are those of the Harmonised System (HS)

♦ The last 2 are subdivisions of the HS which meet the tariff and statistics needs of the EU.

The CN is revised annually on the 1^st January. Furthermore, it is used as the reference for determining customs duty rates to be applied to goods.