IF you look at this coin and see this. (Without knowing the year of this coin) what do you think of it? DDR or MD or DDD? Need helps here Masters.
I'm not a "master" of coins by any means but I would say that its a copper plated zinc cent and the mark to the upper right of Lincoln's head could be a plating blister. You could try a wooden toothpick on it. Just my guess but I'm no expert, interested in what the experienced "masters" think.