# IfcRepresentationMap An _IfcRepresentationMap_ defines the base definition (also referred to as block, cell or macro) called _MappedRepresentation_ within the _MappingOrigin_. The _MappingOrigin_ defines the coordinate system in which the _MappedRepresentation_ is defined. > NOTE Definition according to ISO/CD 10303-43:1992 > A representation map is the identification of a representation and a representation item in that representation for the purpose of mapping. The representation item defines the origin of the mapping. The representation map is used as the source of a mapping by a mapped item. The _RepresentationMap_ is used through an _IfcMappedItem_ in one or several _IfcShapeRepresentation_'s. An Cartesian transformation operator can be applied to transform the _MappedRepresentation_ into the placement coordinate system of the shape representation. The transformation of the representation map is restricted to be a Cartesian transformation mapping (translation, rotation, mirroring and scaling). > NOTE The definition of a mapping which is used to specify a new representation item comprises a representation map and a mapped item entity. Without both entities, the mapping is not fully defined. Two entities are specified to allow the same source representation to be mapped into multiple new representations. > NOTE Entity adapted from **representation_map** defined in ISO 10303-43. > HISTORY New entity in IFC2x. ## Attributes ### MappingOrigin An axis2 placement that defines the position about which the mapped representation is mapped. ### MappedRepresentation A representation that is mapped to at least one mapped item. ### HasShapeAspects Reference to the shape aspect that represents part of the shape or its feature distinctively. > IFC4 CHANGE Inverse attribute added. ### MapUsage ## Formal Propositions ### ApplicableMappedRepr Only representations of type _IfcShapeRepresentation_, or _IfcTopologyRepresentation_ are allowed as _MappedRepresentation_.