10C 1982 MS 67 PCGS No P
Coins minted at Philadelphia have not often featured a mint mark until the late 1970's. In 1979, the United States Mint reversed this policy and began adding a P on Susan B. Anthony dollars which were minted there and in 1980, to every coin with the exception of the cent. However in 1982 collectors noticed that the mint mark was missing from a few of the dimes from Philadelphia. In error the mintmark had not been placed on some of the dies. PCGS has certified just 76 coins at this level with a mere four finer.