DITA provides special elements for defining reusable content. These elements allow for creating standalone, reusable pieces of content that can be referenced and inserted into various topics, documents, or maps.

This is achieved through the <topicref>, <topichead>, <topicmeta>, and <topicgroup> elements.

<topicref> Element:

The <topicref> element is primarily used within DITA maps to reference and organize reusable topics. It acts as a pointer to a DITA topic and is part of the map’s structure. By defining a <topicref> in a DITA map, the associated topic is made available for reuse in different contexts.

        <map>
          <title>My Documentation Map</title>
          <topicref href="reusable-topic.dita"/>
        </map>
    

In this example, the <topicref> element references a DITA topic named “reusable-topic.dita.”

<topichead> Element:

The <topichead> element is used to define a topic’s title and metadata. It’s often employed within DITA maps to specify the title of the referenced topics, contributing to how those topics are displayed in the table of contents or other navigation elements.

        <map>
          <title>My Documentation Map</title>
          <topicref href="reusable-topic.dita">
            <topichead>Introduction to Our Product</topichead>
          </topicref>
        </map>
    

In this example, the <topichead> element defines the title of the referenced topic.

<topicmeta> Element:

The <topicmeta> element is used to provide metadata about a DITA topic. This metadata can include information such as the author, subject, keywords, or any other relevant details about the content. By including this element within topics, it is ensured that essential information travels with the reusable content.

        <topicmeta>
          <author>John Doe</author>
          <keywords>product, documentation, guide</keywords>
        </topicmeta>
    

In this example, the <topicmeta> element contains information about the topic’s author and keywords.

<topicgroup> Element:

The <topicgroup> element is used to group related DITA topics together within a map. It acts as a container for organizing topics and can be helpful when managing sets of reusable content.

        <map>
          <title>My Documentation Map</title>
          <topicgroup>
            <topicref href="topic1.dita"/>
            <topicref href="topic2.dita"/>
          </topicgroup>
        </map>
    

In this example, the <topicgroup> element groups two related DITA topics for organization and reuse.