Most times, this designation will be given some time after after the book has been read and reviewed rather than when a review is first posted.  These are the books that deserve special mention because their impact is so great that these books move us as readers long after the book has been put aside.  The award OUTSTANDING BOOK does not necessarily correspond to a number rating but generally will be chosen from books with a 4-5 rating.  A book with minor flaws can still haunt a reader in ways a book more perfectly executed in its genre may not.  This special mention will be rare, not the expected norm.