For topic references, image references, and other link relationships, resources can
be indirectly addressed by using the @keyref attribute. For content
reference relationships, resources can be indirectly addressed by using the
@conkeyref attribute.
For references to topics, maps, and non-DITA resources, the value of the
@keyref attribute is simply a key name (for example,
keyref="topic-key").
For references to non-topic elements within topics,
the value of the @keyref attribute is a key name, a slash ("/"), and the ID of the target element (for
example, keyref="topic-key/some-element-id".)
<topic id="topicid">
<title>Example referenced topic</title>
<body>
<section id="section-01">Some content.</section>
</body>
</topic>and
this key
definition:<map>
<topicref keys="myexample"
href="file.dita"
/>
</map>A cross reference of the form keyref="myexample/section-01" resolves
to the <section> element in the topic. The key reference is
equivalent to the URI reference
xref="file.dita#topicid/section-01".