Back matter

Back matter is "all content that appears after the last chapter or end of the body matter," in KDP's wording. The elements KDP gives rules for are the bibliography and reference pages, the author bio and the index; each falls on a right-facing page, and KDP adds that "The first section of back matter starts on a right-facing page." The index is set with hanging indentation, first line flush left and following lines indented.

For the author, back matter is where a print edition keeps what serves the reader after the story ends: the about-the-author page, references, and, when a web serial is collected into print, bonus material such as an author's note or a bonus chapter. It pairs with front matter as the book's frame around the body; an epilogue, where one exists, rounds off the story itself rather than the apparatus. The sequence in practice is how to create a print-ready PDF.