The CIS/2 is a set of formal specifications developed to help reduce duplication of effort in the steel design and construction industry. It defines a standard neutral data exchange file format for the sharing of engineering and construction information. The data is stored in neutral data structures in a standardized file format that is independent of the particular application that created the data. This allows for data interchange between any two software applications that have CIS/2 translators. For example, a model can be designed and analyzed in one software application, exported to a CIS/2 file, then imported into a detailing package, eliminating the need to recreate the model in the second application.

The CIS/2 is based upon a Logical Product Model (LPM/5) that defines the neutral data structures of the CIS/2 file. This LPM determines the scope of the engineering information that can be shared among CIS/2 compatible applications. The LPM encompasses more engineering data than does any one application, from the planning stages of the structure, all the way through construction. Thus, each software package will only import and export a subset of the entire LPM/5.

Valid subsets of the LPM/5 that can be exchanged between applications are known as Conformance Classes (CCs). Two CIS/2 compliant software packages are able to interchange data when they support overlapping Conformance Classes. A list of the CCs that an application supports should be available with the application's documentation.