What happened to this cent?

My dad found this in his change the other day. It doesn't have any copper color to it and the strike (?) looks kind of flat to me. I guessed that somebody dipped it in acid or something and it removed the copper layer. He wants to make sure it isn't a super valuable error, so I told him I would bring it to you folks. This pic was the best I could come up with.
2002 D Lincoln cent
2002 D Lincoln cent

Collector of Confederate currency
Quondo omni flunkus moritati
Quondo omni flunkus moritati
0
Comments
the copper plating has been
removed.
Sorry to say it's an alteration,
and not a genuine 'unplated
zinc cent'......
Fred
Quondo omni flunkus moritati
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