The abstract element gml:AbstractGML is “any GML object having identity”. Itacts as the head of an XML Schema substitution group, which may include any element which isa GML feature, or other object, with identity. This is used as a variable in content modelsin GML core and application schemas. It is effectively an abstract superclass for all GMLobjects.
Database handle for the object. It is of XML type ID, so is constrained to beunique in the XML document within which it occurs. An external identifier for the object inthe form of a URI may be constructed using standard XML and XPointer methods. This is doneby concatenating the URI for the document, a fragment separator, and the value of the idattribute.
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<element name="AbstractGML" type="gml:AbstractGMLType" abstract="true" substitutionGroup="gml:AbstractObject"><annotation><documentation>The abstract element gml:AbstractGML is “any GML object having identity”. It acts as the head of an XML Schema substitution group, which may include any element which is a GML feature, or other object, with identity. This is used as a variable in content models in GML core and application schemas. It is effectively an abstract superclass for all GML objects.</documentation></annotation></element>