Machine doubling is! The raised mark appears to be a die gouge. It's not under the "O". It is on the surface of the die, so it doesn't appear through the letter. The reason I quoted a value of 1/2c is because you need to post both sides. For all we know, the obverse has a severe case of road rash. Chris
The 1987 D is a good example of DDD - Die Deterioration Doubling. The D mint mark if exposed to the elements will incur Zinc Rot since the Zinc is exposed. Copper Plated Zinc Cents have this plating issue Here is you picture
Probably a small linear bubble... another plating issue. With no picture of the Reverse side... looks like a normal Cent Value - 1 Cent each