The first of three mint mark types that show a large, engraved D (not punched) showing comparatively long serifs. A good look at this mint mark type compared to the others shows a distinctive concave curve along the lower area of the mint mark near the lower serif.
A number of cent dies during this period, especially 1997, are known to have remnants of a D mint mark on Philadelphia dies. This would indicate that the D mint mark was on the initial design used to create dies, but was removed (mostly) before creating the no-mint mark Philadelphia mint dies.
