Facettierte Boundary Representation  
Faceted Brep 
The IfcFacetedBrep is a manifold solid brep with the restriction that all faces are planar and bounded polygons.
NOTE Use of IfcFacetedBrep is restricted for boundary representation models with planar surfaces only. Those surfaces are implicitly represented by the bounding polygons. The diagram shows the topological and geometric representation items that are used for faceted breps. 

Figure 332 — Diagram showing the use of IfcFacetedBrep 
NOTE Definition according to ISO/CD 1030342:1992
A faceted Brep is a simple form of boundary representation model in which all faces are planar and all edges are straight lines. Unlike the Brep model, edges and vertices are not represented explicitly in the model but are implicitly available through the poly loop entity. A faceted Brep has to meet the same topological constraints as the manifold solid Brep.
The faceted Brep has been introduced in order to support the larger number of systems that allow boundary type solid representations with planar surfaces only.
NOTE Entity adapted from manifold_solid_brep defined in ISO 1030342.
HISTORY New entity in IFC1.0
Informal Propositions:
#  Attribute  Type  Cardinality  Description  G 

IfcRepresentationItem  
LayerAssignment  IfcPresentationLayerAssignment @AssignedItems  S[0:1]  Assignment of the representation item to a single or multiple layer(s). The LayerAssignments can override a LayerAssignments of the IfcRepresentation it is used within the list of Items.
IFC2x3 CHANGE The inverse attribute LayerAssignments has been added. IFC4 CHANGE The inverse attribute LayerAssignment has been restricted to max 1. Upward compatibility for file based exchange is guaranteed.  X  
StyledByItem  IfcStyledItem @Item  S[0:1]  Reference to the IfcStyledItem that provides presentation information to the representation, e.g. a curve style, including colour and thickness to a geometric curve.
IFC2x3 CHANGE The inverse attribute StyledByItem has been added.  X  
IfcGeometricRepresentationItem  
IfcSolidModel  
Dim :=3  IfcDimensionCount  The space dimensionality of this class, it is always 3.  X  
IfcManifoldSolidBrep  
1  Outer  IfcClosedShell  A closed shell defining the exterior boundary of the solid. The shell normal shall point away from the interior of the solid.  X  
IfcFacetedBrep 
<xs:element name="IfcFacetedBrep" type="ifc:IfcFacetedBrep" substitutionGroup="ifc:IfcManifoldSolidBrep" nillable="true"/>
<xs:complexType name="IfcFacetedBrep">
<xs:complexContent>
<xs:extension base="ifc:IfcManifoldSolidBrep"/>
</xs:complexContent>
</xs:complexType>
ENTITY IfcFacetedBrep
SUPERTYPE OF(IfcFacetedBrepWithVoids)
SUBTYPE OF (IfcManifoldSolidBrep);
END_ENTITY;