Additional excise duties imposed by tariff heading, prescribing specific or ad valorem rates tied to processing and classification. The substituted First Schedule prescribes additional excise duties by tariff heading and subheading, linking interpretation to the Central Excise Tariff Act; it sets ad valorem and specific duties or nil rates for identified goods - notably differentiated treatments for sugar types, a detailed array of tobacco products, and extensive textile and fabric categories - with rates contingent on processing, branding and intended use.