Expressing Document Relationships in XML

The basic XML syntax allows for creation of markup languages to convey structure and include content, but doesn't describe relationships between documents or portions of documents. That role is served in core XML by a series of technologies described in W3C Recommendations: XML Base, XML Inclusion (XInclude), and XML Linking Language (XLink). These related technologies establish relationships among resources, resource identifiers, documents, and sections of documents, building on XPath and XPointer.