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

FSCs or as simple as ad valorem payments, their perpetuation relies on the interests of industries whose scope and lifetime they have extended.

ECONOMIST: Economics focus

Rich countries' subsidies are more complicated than simple ad valorem payments.

ECONOMIST: Economics focus

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

There are ad valorem taxes of about 2% as well.

FORBES: We're Headed To $8 Natural Gas

For a period of 20 years the existing Turkish customs tariff shall remain in force throughout the whole of the blue and red areas, as well as in areas (a) and (b), and no increase in the rates of duty or conversions from ad valorem to specific rates shall be made except by agreement between the two powers.

BBC: Map detailing the Sykes-Picot agreement