Pre-appeal deposit requirement: appellants must deposit a prescribed portion of the duty or penalty before filing appeal. A substituted section 35F requires appellants to deposit a prescribed portion of the duty demanded or penalty imposed before the Tribunal or Commissioner (Appeals) will entertain specified appeals; different deposit rates apply by appeal category, an overall monetary cap is prescribed, and the rule does not apply to stay applications and appeals pending before appellate authorities immediately prior to commencement. 'Duty demanded' is defined to include assessment-determined amounts, erroneous Cenvat credit, and amounts recoverable under the Cenvat Credit Rules.