An uncertified copy of an identity document bearing an endorsement of a marriage does not constitute a certificate of registration as contemplated in section 4(8) of the Recognition of Customary Marriages Act 120 of 1998, and therefore does not constitute prima facie proof of a customary marriage. Where the existence of a customary marriage is challenged, the party alleging the marriage must prove not only registration but also that all requirements for a valid customary marriage were met, including compliance with customary law requirements (consent of both spouses, consent of guardian if required, lobola negotiations and payment, and traditional ceremonies). Where a party relies on secondary evidence and its authenticity is challenged, the party must produce the best available evidence and provide corroborating evidence to prove the existence of the marriage. The mere production of an uncertified, disputed identity document, without proof of the underlying customary marriage requirements or corroborating evidence, is insufficient to discharge the onus of proving a customary marriage on a balance of probabilities.