20 Rials - Qaboos 20th National Day, Sultan Qaboos

Issued to mark the twentieth anniversary of Sultan Qaboos bin Said's accession, which followed his overthrow of his father Said bin Taimur in a bloodless palace coup on July 23, 1970. Said bin Taimur had kept Oman in deliberate isolation — fewer than ten kilometers of paved road existed in the entire country at his removal. The anniversary series commemorates the transformation Qaboos initiated almost immediately afterward.

Fr#11a distinguishes this from the standard Fr#11 issue by alloy specification, a detail that surfaces irregularly in auction records.