Since I'm new to this and trying to learn. The letters on the back in states and of seem to be really worn down or just hardly there. Since I don't see any other wear I just wandered about it. Thanks for your help and patience for a newbie!
You'll often find cents with the area around "OF" fairly weak and is due to the design. Simply take a look at the obverse design opposite said area to see why.
From a worn die or possibly grease or other debris got in the way of a complete strike. Not an error though.
O.K. Thank You, I've been trying to go through all my coins before putting them in the bank. This I guess will go in the bank! I'll keep searching.