These minor hits on worthless modern coins are nothing. Maybe the edge of a dime got pressed in there somehow. It didn't come from the mint like that, it is unlikely to be worth more than .05 cents. If you like it, put it in a 2x2 coin flip and save it. Coins are not perfect or impregnable. In fact, they take a great deal of abuse during their life. If you look at every coin with a microscope you are sure to find some tiny flaws or imperfections, or hits, bag marks, damage etc. It's good to have an interest, and it's good observation and it furthers your knowledge. The only problem is, new people are constantly "looking for errors". Because they have been brainwashed by You Tube video propaganda. True mint errors are very rare, difficult to find in circulation, and even when you do find a real error, 99% of the time, it is only minor. I am not singling you out. I am talking about all of the new people who have "error fever".
No other research, right? The fact that a set of dies produces millions of coins says that there should be many more of these in circulation, yet yours is the only one that's ever been found insures that it is not a mint error.