RELAX NG

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. A RELAX NG schema is itself an XML document.

RELAX NG (1997). Articles>Information Design>Standards>XML