1998 D Roosevelt Dime Very Interesting D Mint Mark

Well no more RPMs after 1989. (The mintmark is part of the newer dies design. no longer hand punched) The the mintmark area would be enlarged, then it would be a DDO. But it is normal sized. There is a lot of die wear/DDD and Machine Doubling. Not hub doubling. Die Deterioration is very strong on your coin. But that is not from the die being created like that. The die just got old. Keep in mint the metal movement creates a lot of wear on the dies. Some dies can strike as many as 750K-one million coins before they are retired. (And the dies look very tired when you find examples of the later die states) Also not what the doubled dies look like on the new dimes. After 1972 there are very few DDO / DDRs.
OBV:
http://varietyvista.com/07%20Roosev...Listings.htm
REV:
http://varietyvista.com/07%20Roosev...Listings.htm
On the newer dies look at the locations of the reverse DDRs are. You will discover, your not even looking there.
Take a look, and be surprised.

I was thinking along the same lines as Coop, DDD or possible die scratches (from polishing?).
The secondary lines within the MM (NW-SE) match the direction of the die flow lines almost exactly.