Electronic Cigarettes: Imports, Tariffs, and Data Collection, GAO-15-491R: Published: May 7, 2015. Publicly Released: Jun 8, 2015. “Import volume and tariff revenue for electronic cigarettes, known as e-cigarettes, are unknown, because the Harmonized Tariff Schedule of the United States (HTS)—which is used to classify U.S. imports and exports for tariff and other purposes—does not contain… Continue Reading