Certificate of Origin requirements govern issuance, validity, retrospective issuance and presentation for preferential tariff treatment. The Certificate of Origin must follow Annexure-E, be in English, bear a unique serial number, authorised signature and seal, and state HS code, description, quantity, consignee, exporter/producer/manufacturer, country of origin and origin criteria. It must be issued by the competent authority prior to, at, or within five working days of exportation, may be issued retrospectively for exceptional reasons with the legend 'ISSUED RETROSPECTIVELY' no later than twelve months from shipment, and in case of loss a 'CERTIFIED TRUE COPY' may be issued within the original validity period. Minor clerical discrepancies that do not affect authenticity do not ipso facto invalidate the certificate.