Simple mounting points are often not sufficient in enclosure construction. Entire 1-dimensional or 2-dimensional mounting areas are often used, on which attachments can be moved relatively freely. As in the case of simple mounting points, the class [CNS_CP|4|6] is used for this purpose. In this case, the attachment point defines the origin of a 2-dimensional coordinate system, where the Z-axis is perpendicular to the mounting plane and its X/Y-axis defines the local 2-dimensional coordinate system (typically referred to as a U-V system). Since the same class is used as for mounting points, mounting points can be converted to the other types relatively easily.

These attributes define the type or extent of the mounting line or surface. In selected special cases, it may also be necessary to define a general geometry for mounting surfaces using the Mounting Receptacle Conture attribute. The schema follows that described at Section 5.12.11.8.2, “Definition of outlines / contours”.