Is this just plating blister or is it a lamination error? But why is the bottom half of the S in States completely missing? Just wear? But there's no remnant of the bottom half of the S. The top half of the S is concave, as in indented in; yet, the "blister" is not indented in. And, I can see all of the steps on the Lincoln Memorial, and the other details are sharp. I think there are plating blisters elsewhere on the reverse though.
I was thinking plating blister "Zincoln" with a grease filled bottom S and left part of O (?). Maybe I just put it back in the change jar then...
I'm also guessing this 1992 P cent is not an error. That year has a close AM error and I take it that this "dot" in between doesn't count. Looks like it's just a plating blister...