The obverse i'm not sure if its PMD, but the Reverse is interesting (to me at least). Not sure if it's very common but it looks like you can see parts of the zinc underneath? It's prolly not a DDR but I wanted to get some opinions on this. Thank you.
those are the keywords i was looking for, thank you. Searching Plating Errors I can see some extreme examples of this going wrong. Thank you.
Well, that's one on me I did not know. I always attributed it to just being a not made so well coin. More defective than error. But thanks for the info.