Defined in File Ifc4x1.h
IfcExternalReferenceRelationship: public Ifc4x1::IfcResourceLevelRelationship¶
IfcExternalReferenceRelationship is a relationship entity that enables objects from the IfcResourceObjectSelect to have the ability to be tagged by external references.
NOTE This relationship is used to assign classification, library or document information to entities that do not inherit from IfcRoot. It has a similar functionality as the subtypes of IfcRelAssociates.
HISTORY New Entity in IFC 2x4
An external reference that can be used to tag an object within the range of IfcResourceObjectSelect.
NOTE External references can be a library reference (for example a dictionary or a catalogue reference), a classification reference, or a documentation reference.
Objects within the list of IfcResourceObjectSelect that can be tagged by an external reference to a dictionary, library, catalogue, classification or documentation.
- ::Ifc4x1::IfcExternalReference *