Appendices

The <appendices> element that is available in the DITA bookmap has a special behavior (based on its sibling nodes):

If the bookmap contains <part> elements, the <appendices> will behave as a part.
If the bookmap contains <chapter> (and no <part>) elements, the <appendices> will behave as a chapter.

Note: The behavior includes page-break, numbering, and title rendering.

For example, if I define a bookmap with a <part> element, I will obtain:

<part>
  <chapter/>
    <topicref/>
  <chapter/>
</part>
<appendices>  <!-- Appendices behaves like a Part -->
  <appendix/>  <!-- Appendix behaves like a Chapter -->
  <appendix/>
</appendices>

For another example, if I define a bookmap with a <chapter> element only, I will obtain:

<chapter/>
  <topicref/>
<chapter/>
<appendices>  <!-- Appendices behaves like a Chapter -->
  <appendix/>  <!-- Appendix behaves like a TopicRef -->
  <appendix/>
</appendices>

Warning: If the <appendices> element is not defined and the <appendix> is used directly instead, then it will behave like a Part or Chapter using the same pattern as for <appendices>.

How To Control Page Break Within Appendices

If you define a bookmap with <appendices> and some <appendix> elements, you may want the parent <appendices> to be on a separate page than its children. This is done automatically if the bookmap contains <part> elements. Otherwise, you may need to use the following in your CSS:

*[topicrefclass ~= "bookmap/appendix"]:first-of-type {
  break-before: always;
}