The Organisation of African Unity held its 1978 summit in Khartoum, and Sudan issued this piece to mark the occasion. Whether struck in silver or aluminium remains unresolved in the reference literature — "Prueba" designations from this period and region were sometimes applied to pattern strikes in base metal submitted alongside precious-metal proposals, with no single standard governing which composition advanced to approval.
The Organisation of African Unity held its 1978 summit in Khartoum, and Sudan issued this piece to mark the occasion. Whether struck in silver or aluminium remains unresolved in the reference literature — "Prueba" designations from this period and region were sometimes applied to pattern strikes in base metal submitted alongside precious-metal proposals, with no single standard governing which composition advanced to approval.