Hey Bate, I think you're in reference to the UNITED STATES being affected? That is a "grease filled die strike". The dies are polished to help maintain life and use. Two things happen. The face of the die is polished down, this makes all the devices shallower. Secondly, the diamond paste polish, metal dust, and lubrication grease get pushed into then compacted into the devices. This area happens to be a candidate for a die clash. Where the dies come together without a planchet to strike, they'll imprint each other...this they polish off. Flip the coin over, see the vest opposite that area? The lines on #2 coin, are polishing lines.