It's the "strike-thru" that looks like a grease stain where the red arrow is pointing. I have to plead ignorance of error coins. The picture is from a very popular auction site. I don't know the local rules about linking to other sites on this forum. Sorry. PS: the asking price is $19,995.99, which IMO seems insane for a dirty coin.
I have to go an do my homework now my daddy is calling me thank allI try to come back tommorrow and learn about coins
Not that is is worth the asking price, but it is certified as a "Reverse Strike Thru". He is accepting best offers. Here is the link to the listing http://cgi.ebay.com/2009-50-NGC-MS-...mQQptZCoins_US_Individual?hash=item2557096e13