<topicsubject>The <topicsubject> element identifies the subjects covered by a
topic or map.
In order to identify a primary subject, refer to the subject with the
<topicsubject> itself. Subjects can be identified by @keys
(if defined in the scheme) or, if the subject definition topic exists, by @href (as
with ordinary topic references).
Additional secondary subjects can be specified by nested <subjectref>
elements.
See appendix for information about this element in OASIS document type shells.
+ map/topicref classify-d/topicsubject
In the following example, the map is classified as covering Linux as the primary subject; the
topic "Developing web applications" also covers the secondary web and development subjects. These
subjects (and their keys) are defined externally in a subject scheme map; in order to reference the
subject directly without the subject scheme map, the @href attribute would be used
in place of @keyref.
<map>
<title>Working with Linux</title>
<topicsubject keyref="linux"/>
<!-- ... -->
<topicref href="webapp.dita" navtitle="Developing web applications">
<topicsubject>
<subjectref keyref="web"/>
<subjectref keyref="development"/>
</topicsubject>
<!-- ... -->
</topicref>
<!-- ... -->
</map>The following attributes are available on this element: Universal attribute group, Link relationship attribute group (with a narrowed definition of
@href, given below), @navtitle and @query from Topicref element attributes group, outputclass, @keyref, and @keys. This element also uses
narrowed definitions of @processing-role and @toc (given below) from
Attributes common to many map elements.
@href<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.@processing-role@processing-role is
"resource-only". Otherwise, the definition matches
the one found in Attributes common to many map elements.@toc@toc is "no". See Attributes common to many map elements for a complete definition of
@toc.