BOOK - FrameMaker Book File are the best files that you can use when it comes to generating books and many other large documents. This is a very neat and good extension because it stores references and contains chapters, and much more. You can go online and take advantage of this download at no cost to you. When you are renaming your files you need to make sure that they are referenced in a BOOK file. If you are even using this type of file, then you need to make sure that you add the features that go along with it. It is easy to use, and you will enjoy everything that comes along with it.