Goodreads Librarians Group discussion

I searched "Debt of Bones" today and found these four strange editions:
Debt of Bones 27-C Mixed FD
Debt of Bones 27-C Mixed Prepack
Debt of Bones 36-C Mixed FD
Debt of Bones 36-C Mixed Prepack

The have ISBNs, are all pulished by Tom Doherty Associates, which apparently publishes the imprints Tor, Forge, Orb, Starscape, and Tor Teen. None of them seem to have a source when I look at the edit book page, and they aren't found by ISBN on Amazon or B&N... though there are a handful of hits when I search the ISBN on Google.

If you search for Mixed FD there are a bunch of them that come up.

If looks like the C stands for copy - are these batch orders of books? Anyone have any idea what they are or what should be done with them?

They're displays for bookstores. They should get NAB'd.