DITA includes markup that processors can use to generate reader navigation to or
across DITA topics. Such navigation behaviors include table of contents (TOCs) and
indexes.
Table of contents
Processors can generate a table of contents (TOC) based on the hierarchy of the elements in a DITA map. By default, each <topicref> element in a map represents a node in the TOC. These topic references define a navigation tree.
Indexes
An index can be generated from index entries that occur in topic bodies, topic prologs, or DITA maps.