IfcStyledItem保存产品的表示样式信息，可以显式地用于IfcGeometricRepresentationItem作为分配给产品的IfcShapeRepresentation的一部分，或者通过将表示信息分配给被指定为产品的其他表示的IfcMaterial。
①如果IfcStyledItem在来自IfcProductDefinitionShape的引用中使用，则应提供一个项目。
②如果IfcStyledItem在来自IfcMaterialDefinitionRepresentation的引用中使用，则不应提供任何项目。
●注：定义根据ISO/CD 10303-46:1992
样式项是在表示中使用的几何表示项的表示样式的赋值。
●注：实体改编自ISO10303-46中定义的样式项。
IFC2x2中增加的新实体。
IFC2x2附录1更改了实体IfcStyledItem已变得非抽象并添加了属性名。
如果c2x3 CHANGE The attribute Item已设为可选，则可保证基于文件的交换的向上兼容性。
IFC4更改子类型IfcAnnotationOccurrence并删除其子类型。对所有实例化使用IfcStyledItem。样式的数据类型已更改为IfcStyleAssignmentSelect
使用定义
下图说明了IfcStyledItem在两个使用示例中的用法：
①作为几何表示项的表示
②作为材质定义的表示
注意，新的IfcStyleAssignmentSelect允许直接赋值样式，例如IfcCurveStyle、IfcSurfaceStyle，而不使用中间的IfcPresentationStyleAssignment
| Rule | Description |
|---|---|
| ApplicableItem | A styled item cannot be styled by another styled item. |
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| 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. | 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. | X | |
| IfcStyledItem | |||||
| 1 | Item | IfcRepresentationItem | [0:1] | A geometric representation item to which the style is assigned. | X |
| 2 | Styles | IfcStyleAssignmentSelect | S[1:?] | Representation styles which are assigned, either to an geometric representation item, or to a material definition. | X |
| 3 | Name | IfcLabel | [0:1] | The word, or group of words, by which the styled item is referred to. | X |
EXPRESS Specification
ENTITY IfcStyledItem
SUBTYPE OF (IfcRepresentationItem);
Item : OPTIONAL IfcRepresentationItem;
Styles : SET [1:?] OF IfcStyleAssignmentSelect;
Name : OPTIONAL IfcLabel;
WHERE
ApplicableItem : NOT('IFCPRESENTATIONAPPEARANCERESOURCE.IFCSTYLEDITEM' IN TYPEOF(Item));
END_ENTITY;