The JDK built-in XML Catalog, introduced in JDK 22 with standard DTDs of the Java Platform, now includes the following DTDs and XSDs defined by W3C specifications. These DTDs and XSDs will be loaded locally from the XML Catalog, without requiring network access.

- <a href="https://www.w3.org/XML/1998/namespace.html">The "xml:" Namespace</a>
- <a href="https://www.w3.org/TR/xmlschema-1/">XML Schema Part 1: Structures</a>
- <a href="https://www.w3.org/TR/xmlschema-2/">XML Schema Part 2: Datatypes</a>
- <a href="https://www.w3.org/TR/xhtml1/">XHTML™ 1.0 The Extensible HyperText Markup Language</a>
- <a href="https://www.w3.org/TR/xhtml11/">XHTML™ 1.1 Module-based XHTML</a>
- <a href="http://www.w3.org/2002/xmlspec/dtd/2.10/xmlspec.dtd">XML DTD for W3C specifications</a>