A proof is a production that a publisher issues before the actual trade edition is put out. Here's the link to my collection:
http://www.thedarktower.org/palaver/...-jhanic-proofs
We also have a thread concerning proofs in Calvin's Corner:
http://www.thedarktower.org/palaver/...en-King-Proofs
And an entire forum devoted to them:
http://www.thedarktower.org/palaver/...oofs-and-ARC-s
John