| Name | Type | Cardinality | Description |
| UnboundedGeometry | ocx:UnboundedGeometry_T | [1, 1] | The unbounded surface geometry of the parent element. |
| LimitedBy | LimitedBy | [1, 1] | The references to limiting objects forming a closed contour of the parent element. It is not required that the set of objects is ordered in the correct sequence. |
| ComposedOf | ocx:ComposedOf_T | [1, 1] | Element representing the structural concepts which composes a structure Panel. |
| MassProperties | ocx:MassProperties_T | [0, 1] | The mass properties of structure objects (weight and centre of gravity). These properties are provided by the exporting application and can be used as a quality measure by the receiving application to ensure correctness of the import. Both moulded and volume properties can be provided. The volume properties represent the physical mass property of the structure part, while the moulded properties are idealised. |
| OuterContour | ocx:Contour3D_T | [0, ∞] | The geometry of the outer closed contour limiting a surface, represented by a set of trim curves or a closed curve primitive. |
| PointOnSurface | ocx:Point3D_T | [0, 1] | For multiple surface solutions, a point on the target surface must be provided. |
| StiffenedBy | ocx:StiffenedBy_T | [0, 1] | Structural concept defining the stiffeners which belongs to a panel. |
| SplitBy | ocx:SplitBy_T | [0, 1] | Structural concepts defining the subdivision of a panel into plates split by one or more seams. |
| CutBy | ocx:CutBy_T | [0, 1] | A structural concept defining a cut-out in a surface defined by a parametric hole or a set of generic trim curves. |
| Description | xs:string | [0, 1] | Contains a description of the component its parent represents. The description is stored as a string. You can use this element for whatever purposes you require. This element can be used inside many OCX XML elements but is optional. |
| CustomProperties | ocx:CustomProperties_T | [0, 1] | Container for custom properties. |