Monthly return of excisable goods and CENVAT credit requires itemised production, clearance, duty and credit reporting. Form E.R.-1 is the monthly return for production, clearance and duty accounting of excisable goods and for availment and utilisation of CENVAT credit, requiring itemised entries by tariff, quantities, assessable value, effective duty rates, separate reporting for special clearances, and detailed challan-level duty payment particulars distinguishing basic excise and other duties.