This Recommendation defines the common platform enumeration (CPE) dictionary specification. This includes formally defining the concept of a CPE dictionary@ the rules and policies relating to dictionary instantiation and management@ and the data model that represents all dictionary concepts and relationships. This Recommendation also establishes the concept of an official CPE dictionary@ as well as the process for how organizations can extend the official CPE dictionary using extended CPE dictionaries. As this Recommendation defines these specifications by listing the relevant clauses of the NIST Interagency Report 7697 Common Platform Enumeration: Dictionary Specification version 2.3 and showing whether they are normative or informative@ all other versions are out of the scope of this Recommendation as are all CPE specifications other than CPE dictionary. Operational guidelines@ such as suggested processes for submitting new entries to a dictionary@ are also out of the scope of this Recommendation.