<defaultSubject>
The <defaultSubject>
element is used within an attribute
enumeration to set the default value for the attribute in cases where no value is specified for
the attribute. The default subject must be one of the controlled values that are bound to the
attribute.
See appendix for information about this element in OASIS document type shells.
- map/topicref subjectScheme/defaultSubject
The following example declares that each of the four defined "os" values is valid within the
@platform
attribute; if no value is specified, the default is "linux".
<subjectScheme>
<subjectdef keys="os">
<subjectdef keys="linux"/>
<subjectdef keys="mswin"/>
<subjectdef keys="zos"/>
<subjectdef keys="macos"/>
</subjectdef>
<enumerationdef>
<attributedef name="platform"/>
<defaultSubject keyref="linux"/>
<subjectdef keyref="os"/>
</enumerationdef>
</subjectScheme>
The following attributes are available on this element: Universal attribute group, Link relationship attribute group (with a narrowed definition of
@href
, given below), Topicref element attributes group, outputclass, @keys
, and @keyref
. This
element also uses @processing-role
, @locktitle
, and
@toc
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.