What role does alt text play in conditional processing for accessible DITA content?

Alt text, short for alternative text, plays a vital role in conditional processing for accessible DITA content. It is essential for making your DITA content inclusive and ensuring that it can be consumed by individuals with disabilities, particularly those who rely on screen readers. Alt text provides a textual description of non-text content such as images, charts, or multimedia, making it accessible to those who cannot perceive the visual elements. In the context of conditional processing, alt text helps ensure that the content remains meaningful and informative when conditions hide or filter certain elements.

Alt Text in DITA for Conditional Processing

In DITA, alt text can be specified using the <alt> element. This element allows you to provide a textual alternative to non-text content. When conditions are applied to your DITA content to hide or filter specific elements, alt text ensures that the purpose and meaning of those elements are not lost. For example, if you have an image that is conditionally processed for certain audiences, the alt text can provide a description of the image’s content or function, allowing all users, including those with disabilities, to understand its context.


Here’s an example of how alt text is used in DITA for conditional processing:

<image href="example.png" conkeyref="conditional-key"/>
<alt conref="alt-text.dita"/>

In this example, the <image> element references an image with a conditional key, and the <alt> element references an external DITA topic “alt-text.dita” that contains the alternative text description for the image. When conditional processing is applied based on the specified key, alt text ensures that users with disabilities can access the image’s description, even if the image is hidden or filtered for certain conditions.