causing the coin to have no date. " This anomaly affected less than 250,000 of the 136 million 20p coins minted that year, due to an old obverse (heads side) being mistakenly matched with a new ...
"This issue impacted less than 250,000 coins out of the 136 million 20p pieces minted in 2008 and was a result of pairing the old obverse, or heads side, with the new reverse, or tails side design ...