The following example shows where both approaches may be used. In some cases, for example if a manufacturer has a special identification scheme for a certain type of equipment, it may be necessary to associate an EntityIdentificationSpecification to a specific EntitySpecification.  This type of association would specify that the EntityIdentificationSpecification is only applicable for equipment Entity instances related to the instance of the equipment EntitySpecification and not for equipment Entity instances related to other EquipmentSpecifications below shows the association between an EntityIdentificationSpecification and an EntitySpecification.<br/>