The CDIF family of standards is primarily designed to be used as a description of a mechanism for transferring information between modelling tools. It facilitates a successful transfer when the authors of the importing and exporting tools have nothing in common except an agreement to conform to CDIF. The language that is defined for the Transfer Format also has applicability as a general language for Import/Export from repositories. The CDIF Semantic Metamodel defined for modelling tools also has applicability as the basis of standard definitions for use in repositories. The standards, which form the complete family of CDIF Standards, are documented in ISO/IEC 15474-1:2002, Information technology — CDIF framework — Part 1: Overview. These standards cover the overall framework, the transfer format and the CDIF Semantic Metamodel. The diagram in Figure 1 depicts the various standards that comprise the CDIF family of standard. The shaded box depicts this Standard and its position in the CDIF family of standard. This document describes the way that CDIF metamodels are concretely represented during a transfer and the way that CDIF supports multiple exchange syntaxes and encodings. No specific exchange syntaxes or encodings are described in this document. ISO/IEC 15475-2:2002, Information technology — CDIF transfer format — Part 2: Syntax SYNTAX.1 and ISO/IEC 15475-3:2002, Information technology — CDIF transfer format —Part 3: Encoding ENCODING.1. define one specific CDIF syntax and one specific CDIF encoding. This document is intended to be used by anyone wishing to understand and/or use CDIF. This document provides an introduction to the entire CDIF family of standard. It is suitable for: — Those evaluating CDIF, — Those who wish to understand the principles and concepts of a CDIF transfer, and — Those developing importers and exporters. The documents ISO/IEC 15474-1:2002, Information technology — CDIF framework — Part 1: Overview and ISO/IEC 15474-2:2002, Information technology — CDIF framework — Part 2: Modelling and extensibility should be read first when initially exploring CDIF and before attempting to read other documents in the CDIF family of standard. While there are no specific prerequisites for reading this document, it will be helpful for the reader to have familiarity with the following: — Entity-Relationship-Attribute modelling; — Modelling (CASE) tools; — Information repositories; — Data dictionaries; — Multiple meta-layer modelling; — Formal grammars; — Transfer formats.