:thumb:This may help. http://www.coppercoins.com/diesearch.php?date=1944&date1=1944&thismint=d&thistype=rdodmmom&page=1
We human minds have evolved with patternicity, we seek out patterns in everything and our mind will find meaningful patterns that are known to us in actual meaningless noise. This is just what appears to be an S on the surface of the coin because of such patternicity. It's just like all those people who find "Jesus" in their toast, trees, dirt stains, etc.
I am sorry, I do not see the "S" within the "D". I see what looks like raised dots, but it would be difficult to see them as part of an "S". Jim
Now this post does have some common sense in it and I have tried for years to explain this to some folks. This can happen to almost any one of us no matter who we are if we let our minds stray a little and let our imagination take over. there are quite a few of different types of the 1944 D/S coins and some look so minor I don't try to examine mine.. I always say don't spend so much time with one coin if you want to find a really good one.
Well, if it were to case that the OP does indeed have a D/S variety. Is there any kind of premium if it were to he sold. Seems to me its insignificant of an error to justify the big dollars that the more common D/S would fetch.