Hope Supplying or including an ISBN number is an optional thing as there may not necessarily be such a number for the book. In this case, Carrie, in her submission comments, notes why she didn't include that info. If someone were able to supply one for a book, such as located through a search of the Copyright office, library sites, or any of many other sites, then it can be included. NOte, however, it is an optional field like the long synopsis. So, not being there, isn't of itself a reason for rejecting a book. And, if one were dealing with an older title, there might not be an ISBN number for the book.