Sure.. It was altered after it left the US Mint. It is not a Mint Error of any kind. It was ground down somehow. Only the very bored person that altered it would know how it was done. Sorry
Definitely damaged after it left the mint by a poor lonely individual who's bored to death at the time they did this. Not a Mint error but it is worth face value.
It was damaged on purpose and it looks like they used it as a button before the middle back side part broke off.