Occasionally the metal on the edges will smear as the coin is ejected from the collar. This smearing can push up a little Cu and that can be folded over on the rim. You can also get the same effect when a blank is punched from the rolled sheet. The core layer of a clad coin should be centered but if you look at a lot of clad edges, many times you'll see its not. I dont call it an error, I call it process variability but others may disagree. Regardless, just something minor. As always, save anything you like and find interesting