1984 P Roosevelt Dime Possible Error Mispunch Or Something Else.

to CCF. Looks like a minor MAD,misaligned die.
John1

I agree with the misaligned die response but you might get more responses in the Modern Coin forum.

There is also another even that will altered the outer edge of the rim. It is called a tilted die issue. The tilt (Because the die is not vertical) allows some of the rim near the edge of the coin to rise upward uncontrolled. It for a fin:

What does a fin look like?


Note the fin is raised above the rim and thin. The fin can be flatten in time and look like the example on your coin. Thus when the flatten, the premium for these are gone. (Probably the biggest reason the fin is flatten, it the rolling process will alter them)