Specialized elements and attributes in DITA are validated during authoring through a combination of mechanisms to ensure that the content adheres to the defined specialization rules and guidelines. Here’s an overview of the validation process:

Specialization Rules: Authors follow the specialization rules and guidelines defined for their DITA documents. These rules specify how specialized elements and attributes should be used, including constraints, default values, and any allowed variations.

Authoring Tools: Many DITA authoring tools provide real-time validation and feedback to authors as they create content. These tools can highlight errors or issues related to specialized elements and attributes, helping authors correct them on the fly.

Schema Validation: DITA documents are typically validated against a DTD or XML Schema. This process checks if the document structure conforms to the DITA specialization rules, including the use of specialized elements and attributes.

Schematron Rules: Schematron is often used to define custom validation rules specific to the organization’s DITA specialization. These rules can check for more complex conditions and provide detailed feedback to authors when they violate the specialization rules.

Example:

Suppose you have a specialization for a <product-description> element in your DITA project. The specialization may require specific attributes like product-type and product-version. The following HTML example illustrates how a DITA document can use this specialized element and its attributes:

<!-- Using the specialized DITA element  -->
<product-description product-type="Smartphone" product-version="5.0">
  <title>Product X Features</title>
  <description>
    <p>Product X is a state-of-the-art smartphone with advanced features.</p>
    <p>It comes with a high-resolution screen and an improved camera.</p>
  </description>
</product-description>