This specification is designed to be incorporated into a contract to define the technical requirements to be met when it is desired to purchase product definition data or product data in digital form. IGES is a specification for representing digital product definition data in a neutral, public domain format. IGES provides a neutral format for the representation and transfer of vector graphics data used for illustration purposes between CAD systems and application programs. Information is transferred by entities that represent geometry, annotation entity, attribute, and logical relationships of the product model. IGES files are composed of five sections: start, global, DE, PD, and terminate.

This specification defines the technical requirements for the exchange of digital product data in specific application subsets of IGES. The essential content and general requirements of application subsets are given by this specification and specific application subsets are identified. The definition of the class 5 3D Piping and class 6 LEP APs are identified by this specification. In particular the definition and use of the following specific application areas are defined:

a. Class 1 - technical illustration subset

b. Class 2 - engineering drawing subset

c. Class 3 - electrical/electronic applications subset (Withdrawn)

d. Class 4 - geometry for NC manufacturing subset

e. Class 5 - 3D piping application protocol (AP)

f. Class 6 - Layered Electrical Product (LEP) Application Protocol (AP

g. Class 7 - 3D geometry subset

No new IGES APs are planned. All future IGES APs will be continued in STEP.

Assuring completeness of information exchange with the subset concept relies on a careful encoding of the information into the IGES entities. This specification used the subset concept as a first attempt at this encoding. A more rigorous method has been developed called an application protocol. It involves a formal information model with the rigorous mapping to the IGES entities; see ANS US PRO/IPO for further details.