The tax may be levied as a percentage of the value of the imports, which is called an AD valorem tariff.

税费可以按照进口商品价值的一定的百分比来征收，这称为从价关税。

youdao

A compound tariff is a combination of a specific and an AD valorem tariff.

复合关税是从价税与从量税两种关税相结合所征收的关税。

youdao

If the change of tariff classification does not show substantive change, it takes AD valorem percentage, production or processing procedures as replenished standard.

税则归类改变不能反映实质性改变的，以从价百分比、制造或者加工工序等为补充标准。

youdao

To insulate domestic ethanol producers from competitors in Colombia and Brazil, the government imposes a 54-cent-per-gallon tariff and a 2.5 percent ad valorem tax on ethanol imports.

FORBES: Senators Back Legislation to End Ethanol Subsidy

Then there's a 54-cent tariff (not including a 2.5% ad valorem levy) to keep cheaper Brazilian ethanol out of the country.

FORBES: Field of Dreamers