1990 P LMC Help. DDD And.

Hi all, first time posting though I've already learned so much from lurking around the shadows here this summer. (Thanks coop, john1, and few others) I've just.started the hobby and love it. I was a dive master once and developed a trained eye to see and show sea critters that were invisible to my divers and now I find myself staring at one penny for an hour sometimes searching and learning. It's unbelievable just how many errors and variations and reasons for them all I never in a million years would have thought there was this much to it. It's awesome. Anyhow thanks for sharing and having me on board here.

The 1990 I have before me now is troubling me because it looks like it was pressed after the (and I still don't know exactly the term for this) concave bit on the right rim. I see what I believe to be DDD, MAD prevention doubling of the letters but I don't understand how they are on top of the shallow trenches rim area. At first I thought it was, and very well still is, from the roller fingers after the wrapper of course being rolled and pressed but I would think that would show on top of all the lettering. Anyhow thanks for the help and happy hunting.