Conclusive effect of discharge certificate bars further duty, interest, penalty and prosecution for declared matters and periods. Section 129 gives a discharge certificate conclusive effect for the matters and time periods stated, barring further liability for duty, interest or penalty, barring prosecution under the indirect tax enactment for those matters and periods, and preventing reopening of those matters and periods. Sub-section (2) preserves that issuance does not imply officer acquiescence, does not bar show cause notices for the same matter in subsequent periods or for different matters in the same period, and treats voluntary disclosures later found false within one year as if never made, allowing proceedings to be instituted.