`<unknown>`

The <unknown> element is an open extension that enables information architects to incorporate XML fragments in DITA topics.

Usage information

The <unknown> element is intended primarily as a base for specialization. It might also be used in automatically-generated DITA topics or DITA used as a data-exchange format.

Processing expectations

Processors ignore the <unknown> element unless otherwise instructed.

Attributes

The following attributes are available on this element: universal attributes.

Example

The following code sample shows a specialized <unknown> element that contains non-DITA content:

<body>
  <my-unknown class="+ topic/unknown mything/my-unknown ">
    <thing value="4"/>
    <otherthing value="16"/>
  </my-unknown>
</body>

By definition, the content of <unknown> can only be understood by DITA processors as unknown XML. This means that processors generally ignore this content unless they are configured to recognize the <my-unknown> specialization.