Ensuring that external links remain valid and up-to-date in DITA documentation is crucial for providing accurate and reliable information to your users. When dealing with external resources, such as websites or documents, here are some strategies to maintain the integrity of your links:

Regularly Verify Links: It’s essential to regularly check the links in your DITA documentation to confirm that they are still functional. Dead or broken links can frustrate users and damage the credibility of your content. Automated link checking tools can help identify broken links efficiently.

Use Relative Paths: Whenever possible, use relative paths for your links. This means specifying the path relative to the location of the DITA file. Relative paths are more resilient to changes in the directory structure of your documentation, reducing the chances of broken links. For example:

<link href="../documents/user-manual.pdf">Download User Manual</link>

Update Links When Resources Change: When the external resources you link to undergo changes, ensure that your links are updated accordingly. If a website URL changes or a document is replaced with an updated version, reflect these changes in your DITA documentation.

By following these practices, you can help maintain the validity and currency of external links in your DITA documentation, ensuring a seamless and trustworthy user experience.