If you're talking about the line inside of the rim, it's Post Strike Damage. It looks like the coin was on the end of a roll and the crimping jaws made contact with the coin. I don't see anything on the coin that would be thought of as an error.
ANA ID: 3203813 - CONECA ID: N-5637 Clean a coin that may be worth collecting? Please DON'T! When in doubt, leave it dirty!!

























