Harmonized Tariff Schedule of the United States
The Harmonized Tariff Schedule of the United States (HTSUS), also referred to as the Harmonized Tariff Schedule of the United States Annotated (HTSA), is the primary resource for determining tariff (customs duties) classifications for goods imported into the United States. It can also be used in place of Schedule B for classifying goods exported from the United States to foreign countries.
Source: Wikipedia — Harmonized Tariff Schedule of the United States (CC BY-SA 4.0)