Duty on value addition: revised percentage-based rates with procedural refund and account-credit options for excise exemption. Replaces exemption tied to duty paid with calculation of duty payable on value addition determined as specified percentage rates by Chapter and description; limits payable duty to duty actually paid excluding CENVAT credit where higher, mandates exhaustion of CENVAT credit when all goods are exempt, prescribes monthly reporting and refund or account-current credit procedures subject to verification and recovery rules, and provides an application-based special-rate mechanism reflecting actual value addition with provisional refund and government control over fixation.