Topic properties in topics and maps

The properties of a topic can be specified in the topic itself or on references to the topic within maps.

Within a topic, properties can be expressed using metadata attributes on the topic element or using publication, management, or metadata elements in the topic prolog.

Within a map, the same properties can be expressed on the topicref element that refers to the topic. That is, the topicref attributes and the topicref subelements within the topicmeta container apply to the referenced topic. In addition, the metadata properties map or topicref element set the default properties for nested topicref elements within the map hierarchy. Because the topics in a branch of the navigation hierarchy typically have common subject or properties, this mechanism provides a convenient way to set the properties for a set of topics.

If a property is set in both the map and topic, the map properties are additive if the property (such as the audience type) takes a list of values. If, instead, the property (such as the importance) takes a single value, the map property overrides the topic property.

Example of audience metadata in prolog and body

The practice of providing full metadata in the prolog and referencing it from attributes when a subset of metadata applies is not a best practice. Prolog metadata and attribute metadata can be used and expressed independently. The coordination shown here is possible but is not required.

<prolog>
  <metadata>
    <audience name="AdminNovice"
              type="administrator"
              job="customizing"
              experiencelevel="novice">

  </metadata>
</prolog>
....
<p audience="AdminNovice ProgrammerExp">This paragraph applies to both 
novice administrators and expert programmers</p>