<?xml version="1.0"?> <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"> <book><chapter><title>Required Chapter</title><para> At least one chapter, reference, part, or article is required in a book. </para></chapter><appendix><title>Demonstration Appendix</title><para> This appendix demonstrates an appendix in a book. It has the same broad content model as a chapter. </para></appendix></book>