This part of ISO 13584 specifies an application programming interface that enables an application program to generate geometric models that are independent of the target user system. The interface allows portability of programs that describe parametric shape representations of parts families held in an ISO 13584 parts library.

The following are within the scope of this International Standard:

• programs to generate geometric representations within a modelling system that are independent of the target system,
• programs that specify geometric representations that are created through constraint-based geometric definitions,
• programs that structure geometric representations created independently of the target system,
• programs that specify presentation style attributes for symbolic visualisation of representations created,
• programs that support technical drawing standard conventions for shape representation, including a 2D hidden line mechanism.

The following are outside the scope of this International Standard:

• The precise control of the image to be displayed on the receiving system devices,
• The precise definition of the data that shall be created on the receiving system,
• The storage of a parametric model on the receiving system.