Class PSRType

                    object --+        
                             |        
              Element'.Element --+    
                                 |    
IdentifiedObject'.IdentifiedObject --+
                                     |
                                    PSRType

Classifying instances of the same class, e.g. overhead and underground ACLineSegments. This classification mechanism is intended to provide flexibility outside the scope of this standard, i.e. provide customisation that is non standard.