feature.xsd See ISO/DIS 19136 Clause 9. A GML feature is a (representation of a) identifiable real-world object in a selected domain of discourse. The feature schema provides a framework for the creation of GML features and feature collections. GML is an OGC Standard. Copyright (c) 2007,2010 Open Geospatial Consortium, Inc. All Rights Reserved. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ . The basic feature model is given by the gml:AbstractFeatureType. The content model for gml:AbstractFeatureType adds two specific properties suitable for geographic features to the content model defined in gml:AbstractGMLType. The value of the gml:boundedBy property describes an envelope that encloses the entire feature instance, and is primarily useful for supporting rapid searching for features that occur in a particular location. The value of the gml:location property describes the extent, position or relative location of the feature. This abstract element serves as the head of a substitution group which may contain any elements whose content model is derived from gml:AbstractFeatureType. This may be used as a variable in the construction of content models. gml:AbstractFeature may be thought of as "anything that is a GML feature" and may be used to define variables or templates in which the value of a GML property is "any feature". This occurs in particular in a GML feature collection where the feature member properties contain one or multiple copies of gml:AbstractFeature respectively. This property describes the minimum bounding box or rectangle that encloses the entire feature. gml:EnvelopeWithTimePeriod is provided for envelopes that include a temporal extent. It adds two time position properties, gml:beginPosition and gml:endPosition, which describe the extent of a time-envelope. Since gml:EnvelopeWithTimePeriod is assigned to the substitution group headed by gml:Envelope, it may be used whenever gml:Envelope is valid. The gml:locationName property element is a convenience property where the text value describes the location of the feature. If the location names are selected from a controlled list, then the list shall be identified in the codeSpace attribute. The gml:locationReference property element is a convenience property where the text value referenced by the xlink:href attribute describes the location of the feature. To create a collection of GML features, a property type shall be derived by extension from gml:AbstractFeatureMemberType. By default, this abstract property type does not imply any ownership of the features in the collection. The owns attribute of gml:OwnershipAttributeGroup may be used on a property element instance to assert ownership of a feature in the collection. A collection shall not own a feature already owned by another object.