Placement of such components may be explicitly defined using IfcLocalPlacement relative to the enclosing IfcElementType, or implicitly defined if IfcElement.ObjectPlacement is null.
If an occurrence is instantiated of the given IfcElementType, then such occurrence must include equivalent aggregated elements with names corresponding to those within the element type.
The following diagram shows the generic classes and relationships used when applying this concept.
In addition, concepts may have particular importance to common or standardised industry practices and scenarios. For these specific usage scenarios, the table below shows a recommended list of general usage patterns that users may adopt.