###### 3.1.5.2.1 subjectref

The <subjectref> element identifies a subject to classify content. The <subjectref> can identify the subject with a keyref attribute (if the scheme has a <subjectdef> with a keys attribute that assigns a key to the subject) or an href attribute (if the scheme is not available and a topic exists that defines the subject).

###### Contains

Doctype | Content model
classifyMap | ( (topicmeta) (optional) then (data or data-about) (any number) )

###### Contained by

Doctype | Content model
classifyMap | topicsubject, topicapply, subjectCell

###### Inheritance

+ map/topicref classify-d/subjectref

###### Example

In the following example, the map is classified as covering the Linux subject and the "Developing web applications" topic as covering the 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>

###### Attributes

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 3.4.2.1 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 3.4.2.2 The keys attribute for details on how to use the keys attribute. | NMTOKEN | #IMPLIED | No
keyref | Keyref provides a redirectable reference based on a key defined within a map. See 3.4.2.3 The keyref attribute for information on using this attribute. | CDATA | #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. The processing default is "unordered", although no default is specified in the DTD or Schema. unordered Indicates that the order of the child topics is not significant. sequence Indicates that the order of the child topics is significant; output processors will typically link between them in order. choice Indicates that one of the children should be selected. family Represents a tight grouping in which each of the referenced topics not only relates to the current topic but also relate to each other. Usage of the collection-type attribute on <reltable> and <relcolspec> is currently undefined and reserved for future use. | (unordered | sequence | choice | family | -dita-use-​conref-​target) | #IMPLIED | No
type | Describes the target of a reference. See 3.4.2.8 The type attribute for detailed information on supported values and processing implications. | CDATA | #IMPLIED | No
processing-role | Describes the processing role of the referenced topic. The default for this attribute on this element is "resource-only". normal Normal topic that is a readable part of the information. resource-only The topic is used as a resource for processing purposes, but is not a readable unit of information on its own. This topic should not be included in a rendered table of contents, and the topic should not be rendered on its own. | (normal | resource-only | -dita-use-​conref-​target) | resource-only | No
scope | The scope attribute identifies the closeness of the relationship between the current document and the target resource. See 3.4.2.10 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 3.4.2.9 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 A topic can only be linked to and cannot link to other topics. sourceonly A topic cannot be linked to but can link to other topics. normal A topic can be linked to and can link to other topics. Use this to override the linking value of a parent topic. none A topic cannot be linked to or link to other topics. | (targetonly | sourceonly | normal | none | -dita-use-​conref-​target) | #IMPLIED | No
toc | Specifies whether a topic appears in the table of contents (toc); on this element the default is no. This value defaults to no for elements such as reltable, which typically cannot appear in the toc, and for elements such as glossref that generally are not desired in the toc. | (yes | no | -dita-use-​conref-​target) | "no" | No
univ-atts attribute group (includes select-atts, id-atts, and localization-atts groups) | A set of related attributes, described in 3.4.1.3 univ-atts attribute group |  |  |
global-atts attribute group (xtrf, xtrc) | A set of related attributes, described in 3.4.1.2 global-atts attribute group |  |  |
class, outputclass | Common attributes described in 3.4.1.9 Other common DITA attributes |  |  |

Previous Topic: 3.1.5.2 Classification domain elements

Next Topic: 3.1.5.2.2 topicapply

Parent Topic: 3.1.5.2 Classification domain elements

Sibling Topics:

3.1.5.2.2 topicapply

3.1.5.2.3 topicsubject

3.1.5.2.4 topicSubjectTable

3.1.5.2.5 topicSubjectHeader

3.1.5.2.6 topicSubjectRow

3.1.5.2.7 topicCell

3.1.5.2.8 subjectCell