Definitions for "Valid XML"
Keywords:  constraints, schema, dtd, xml, bu'a
An XML document that has an associated document type declaration and complies with the constraints expressed in it. For more information visit the World Wide Web Consortium pages on XML.
XML documents are said to be "valid" when they include a reference to an internal or external Document Type Definition (DTD) file.
A well-formed Extensible Markup Language (XML) document that conforms to a specific set of constraints, usually defined in an XML Schema.