The book named “Words of Mormon” is temporally out of place. It sits in between the end of the small plates and Mormon’s work abridging the large plates. In addition to being out of sequential order, it is out of writing order. Mormon says that he is about to deliver his record, which is the Book of Mormon, to his son, Moroni. Mormon is clear that it is written after most of the destruction of the Nephites. Since both Mormon and Moroni survived the final battle, it may be assumed that it was written at that time. It is likely the very last thing Mormon wrote for his book.
With a title of “Words of Mormon,” it is also a self-declared anomaly. This isn’t a named book in Mormon’s work. It isn’t part of the small plates, although the first half of Words of Mormon speaks of the small plates. This is exactly what it says it is. It is a few words written as an introduction. It was sufficiently hard to classify that when Oliver Cowdery was writing in the chapter numbers; he originally had it as chapter II of Omni, and the first book of Mosiah as chapter III. He realized his mistake and fixed the names. Nevertheless, it highlights this writing’s anomalous status.