3.2.1 Predefined Type

You can define the types via Modify → BIM... → Predefined type. For example, an IfcMember with the Enum type RAFTER can be specified as a rafter.

If there is no suitable type in the enumeration, this can be set to USERDEFINED and a user-defined object type can be set.

Object type:
The type designates a specific type that describes the object in more detail. In particular, it contains the user-defined type if the enumeration of the PredefinedType attribute is set to USERDEFINED.

Existing PredefinedTypes are adopted when importing an IFC file.

Example IfcBeam (Ifc documentation):
IFC documentation