gml:AbstractCRS specifies a coordinate reference system which is usually singlebut may be compound. This abstract complex type shall not be used, extended, or restricted,in a GML Application Schema, to define a concrete subtype with a meaning equivalent to aconcrete subtype specified in this document.
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.
Source
<element name="AbstractCRS" type="gml:AbstractCRSType" abstract="true" substitutionGroup="gml:Definition"><annotation><documentation>gml:AbstractCRS specifies a coordinate reference system which is usually single but may be compound. This abstract complex type shall not be used, extended, or restricted, in a GML Application Schema, to define a concrete subtype with a meaning equivalent to a concrete subtype specified in this document.</documentation></annotation></element>