The Harmonized Commodity Description and Coding System, also known as the Harmonized System (HS) of tariff nomenclature is an internationally standardized system of names and numbers to classify traded products. It came into effect in 1988 and has since been developed and maintained by the World Customs Organization (WCO) (formerly the Customs Co-operation Council), an independent intergovernmental organization based in Brussels, Belgium, with over 200 member countries. Structure The HS is organized logically by economic activity or component material. For example, animals and animal products are found in one section of the HS, while machinery and mechanical appliances are found in another. The HS is organized into 21 sections, which are subdivided into 99 chapters. The 99 HS chapters are further subdivided into 1,244 headings and 5224 subheadings. Section and Chapter titles describe broad categories of goods, while headings and subheadings describe products in more detail. Generally, HS sections and chapters are arranged in order of a product's degree of manufacture or in terms of its technological complexity. Natural commodities, such as live animals and vegetables, for example, are described in the early sections of the HS, whereas more evolved goods such as machinery and precision instruments are described in later sections. Chapters within the individual sections are also usually organized in order of complexity or degree of manufacture. For example, within Section X (Pulp of wood or of other fibrous cellulosic material; Recovered (waste and scrap) paper or paperboard; Paper and paperboard and articles thereof), Chapter 47 provides for pulp of wood or of other fibrous cellulosic materials, whereas Chapter 49 covers printed books, newspapers, and other printed matter. Finally, the headings within individual Chapters follow a similar order. For example, the first heading in Chapter 50 (Silk) provides for silk worm cocoons while articles made of silk are covered by the chapter's later headings. The HS code consists of 6-digits. The first two digits designate the HS Chapter. The second two digits designate the HS heading. The third two digits designate the HS subheading. HS code 1006.30, for example indicates Chapter 10 (Cereals), Heading 06 (Rice), and Subheading 30 (Semi-milled or wholly milled rice, whether or not polished or glazed). In addition to the HS codes and commodity descriptions, each Section and Chapter of the HS is prefaced by Legal Notes, which are designed to clarify the proper classification of goods. To ensure harmonization, the contracting parties to