units.xsd v3.0 draft last updated 2002/04/22 GML 3.0 candidate schema. Copyright (c) 2002 OGC, All Rights Reserved. This schema encodes the Extent (EX_) package of OGC Abstract Specification Topic 11 (ISO 19115). Information about spatial, vertical, and temporal extent. Constraints: At least one of the elements "description", "GeographicElement", TemporalElement", and "VerticalElement" must be included, but more that one can be included. Furthermore, more than one GeographicElement", TemporalElement", and/or "VerticalElement" can be included. Geographic area of the dataset. To be supplied. To be supplied. To be supplied. To be supplied. To be supplied. To be supplied.