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. The process of assigning HS codes is known as "HS Classification". All products can be classified in the HS by using the General Rules for the Interpretation of the Harmonized System ("GRI"). HS codes can be determined by a variety of factors including a product's composition, its form and its function.