GRG is the XML Schema Implementation of Geographic Information, Procedures for item registration documented in ISO 19135:2005.GRG includes all the definitions of http://www.isotc211.org/2005/grg namespace. The root document of this namespace is the file grg.xsd. This register.xsd XML schema implements all the UML classes of the register schema defined in Clause 8 of ISO 19135:2005.