The <relatedSubjects> element establishes associative relationships between each child subject and every other child subject (unless the association is restricted by the linking attribute of the subjects).
For filtering and flagging, processors need only inspect the subordinate hierarchies under category subjects that are bound to attributes. Filtering and flagging processors do not have to understand specific types of relationships. Explicit relationships are useful primarily for information viewers with advanced capabilities.
The content provider can identify the relationship by specifying a keys attribute, label the relationship by specifying a navtitle element or attribute, and provide a consensus definition of the relationship including by referencing a topic. If the relationship has an identifying key, the content provider can use the keyref attribute to specify the same relationship for different subjects.
|subjectScheme||( (data or data-about or subjectdef or topicref or (anchorref or keydef or mapref or topicgroup or topichead or topicset or topicsetref) ) (any number) )|
- map/topicref subjectScheme/relatedSubjects
<subjectScheme> <!-- ... --> <relatedSubjects> <subjectdef keys="linux" navtitle="Linux"/> <subjectdef keys="apacheweb" navtitle="Apache Web Server"/> <subjectdef keys="mysql" navtitle="MySQL Database"/> </relatedSubjects> <!-- ... --> </subjectScheme>
|Name||Description||Data Type||Default Value||Required?|
|navtitle||Specifies the title of the topic as it will appear in the navigation or tables of contents that are generated from the map. Beginning with DITA 1.2, the preferred way to specify the navigation title in a map is with the navtitle element, available inside the topicmeta element.||CDATA||#IMPLIED||No|
|href||A pointer to the resource represented by the <topicref>. See The href attribute for detailed information on supported values and processing implications. References to DITA content cannot be below the topic level: that is, you cannot reference individual elements inside a topic. References to content other than DITA topics should use the format attribute to identify the kind of resource being referenced.||CDATA||#IMPLIED||No|
|keys||Introduces one or more global identifiers for a resource referenced from a map. See The keys attribute for details on how to use the keys attribute.||NMTOKEN||#IMPLIED||No|
|processing-role||Describes the processing role of the referenced topic. The
processing default is "normal".
If the value is not specified locally, but
is specified on an ancestor, the value will cascade from the closest
||(normal | resource-only | -dita-use-conref-target)||#IMPLIED||No|
|query||This attribute is deprecated. It may be removed in the future.||CDATA||#IMPLIED||No|
|collection-type||Collection types describe how links relate to each other.
||(unordered | sequence | choice | family | -dita-use-conref-target)||family||No|
|type||Describes the target of a reference. See The type attribute for detailed information on supported values and processing implications.||CDATA||#IMPLIED||No|
|scope||The scope attribute identifies the closeness of the relationship between the current document and the target resource. See The scope attribute for more information on values.||(local | peer | external | -dita-use-conref-target)||#IMPLIED||No|
|format||The format attribute identifies the format of the resource being referenced. See The format attribute for details on supported values.||CDATA||#IMPLIED||No|
|linking||Defines some specific linking characteristics of a
topic's current location in the map.
||(targetonly | sourceonly | normal | none | -dita-use-conref-target)||normal||No|
|univ-atts attribute group (includes select-atts, id-atts, and localization-atts groups)||A set of related attributes, described in univ-atts attribute group|
|global-atts attribute group (xtrf, xtrc)||A set of related attributes, described in global-atts attribute group|
|class, outputclass, keyref||Keyref provides a redirectable reference based on a key defined within a map. See The keyref attribute for information on using this attribute. Class and outputclass are described in Other common DITA attributes|