Indeed, in DITA XML, you can effectively use links to provide citations, sources, or references to external documents or standards. This is a valuable feature for creating documentation that relies on external sources for references, sources, or further reading. The <xref> element plays a key role in linking to external documents or standards. You can specify the target URL or location using the href attribute, and provide a title or label for the link to make it meaningful to users.

For instance, you can link to a relevant external standard by using the <xref> element in your DITA content, like this:

<p>Our product adheres to the <xref href="https://www.example-standards.com/standard123.pdf" scope="external">Standard 123</xref> for quality assurance.</p>

In this example, “Standard 123” is a link to an external PDF document at “https://www.example-standards.com/standard123.pdf.” This allows users to easily access and reference external standards or documents within the context of your DITA documentation.