Google requires an ISBN code for books. This is not the same as the SKU for the product. I'm getting flagged on these products in the Google Feed. I have Product Field 11 defined as "Mfg Part Number" in the Google Product Search/Merchant Center Configuration. Can I use this same field for the ISBN code? If so do I need to preface the code with "ISBN:"?
Alternatively do I need to designate a Product Field explicitly as "ISBN Code" for Google?