gml:AffineCS is a two- or three-dimensional coordinate system with straightaxes that are not necessarily orthogonal. An AffineCS shall have two or three gml:axisproperty elements; the number of property elements shall equal the dimension of theCS.
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="AffineCS" type="gml:AffineCSType" substitutionGroup="gml:AbstractCoordinateSystem"><annotation><documentation>gml:AffineCS is a two- or three-dimensional coordinate system with straight axes that are not necessarily orthogonal. An AffineCS shall have two or three gml:axis property elements; the number of property elements shall equal the dimension of the CS.</documentation></annotation></element>