(
REgular
LAnguage Description for
XML
Next
Generation) An XML schema from OASIS that is based on RELAX and TREX. It is easier to learn than the W3C's XSD XML schema and adds missing features. For example, RELAX NG allows more complex relationships between attributes and elements to be expressed. RELAX was developed by Murata Makoto and the Japanese Standards Association, and TREX (Tree Regular Expressions) was created by James Clark. RELAX NG schemas are named with the file extensions .RNG or .RNC. See
XML schema.