default namespace = "http://www.isotc211.org/2005/gmx"
namespace gco = "http://www.isotc211.org/2005/gco"
namespace gmd = "http://www.isotc211.org/2005/gmd"
namespace gml = "http://www.opengis.net/gml/3.2"
namespace xsi = "http://www.w3.org/2001/XMLSchema-instance"

start =
  element CT_CodelistCatalogue {
    attribute xsi:schemaLocation { text }?,
    element name { gco.CharacterString },
    element scope { gco.CharacterString },
    element fieldOfApplication { gco.CharacterString },
    element versionNumber { gco.CharacterString },
    element versionDate {
      element gco:Date { xsd:date }
      | element gco:DateTime { xsd:dateTime }
    },
    element language {
      element gmd:LanguageCode {
        attribute codeList { xsd:anyURI },
        attribute codeListValue { xsd:NCName },
        text
      }
    }?,
    element characterSet {
      element gmd:MD_CharacterSetCode {
        attribute codeList { xsd:anyURI },
        attribute codeListValue { xsd:NCName },
        text
      }
    }?,
    element codelistItem {
      element CodeListDictionary {
        attribute gml:id { xsd:NCName },
        gml.description,
        gml.identifier,
        element codeEntry {
          element CodeDefinition {
            attribute gml:id { xsd:NCName },
            gml.description,
            gml.identifier
          }
        }+
      }
    }+
  }
gco.CharacterString = element gco:CharacterString { text }
gml.description = element gml:description { text }
gml.identifier =
  element gml:identifier {
    attribute codeSpace { text },
    xsd:NMTOKEN
  }