Similar to front matter, there is material you might wish to include after your book's final <chapter> or your article's final <section>. Possibilities to place in a <backmatter> include <appendix>, <references>, <glossary>, <solutions>, <index>, and <colophon>. There are empty tags you can place into an appendix to generate lists of notation, or lists of particular elements of your choice, such as a list of figures. A similar empty element actually generates the index, <index-list>, but you will almost always want to place it into the <index> division. See Section 5.24 for details on the back matter generally. Also, be sure to read about the powerful and flexible automatic list feature (Section 5.27), which is not restricted to just the back matter.