The Harmonized System Codes (HS Code) is a standard issued by the World Customs Organization (WCO) to unify the classification of the goods. These are six digit codes for identifying different products across the world. The country using these HS codes can suffix additional digits to the existing six digits according to their needs.
One can use HS code to search the tariff for imported goods at the customs website; or one can enter the key word of the goods (for example steel for hot trolled steel sheets) and locate the correct tariff and HS Code. The link is here.
The HS Code books prepared by the customs authority can be bought at Customs Authority Office.
One can also locate HS Codes here.