What is the customs clearance form in the United States?

Release form: also known as release form in the industry, it can be divided into paperless release form and paper release form, indicating that the goods have been released by the customs. The United States Customs is divided into two parts, namely, the Customs Border Protection Agency and the Immigration Customs Enforcement Agency. The US Customs is responsible for border enforcement and case investigation respectively, and was established in March 2003 1.