PUBLIC MARKS with tags xml & relaxng

RELAX NG is a simple schema language for XML, based on [RELAX] and [TREX]. A RELAX NG schema specifies a pattern for the structure and content of an XML document. A RELAX NG schema thus identifies a class of XML documents consisting of those documents that match the pattern. Two syntaxes have been defined for RELAX NG. The original syntax uses XML; with this syntax an RELAX NG schema is itself an XML document. Subsequently, a compact non-XML syntax has been defined. This document is a tutorial for RELAX NG version 1.0 using the XML syntax.

Documentation Oreilly de RelaxNG par Eric van der Vlist de xmlfr.org

Site du langage de description relaxNG pour le XML (standard ISO)