This report defines the Common Platform Enumeration (CPE) Dictionary version 2.3 specification. The CPE Dictionary Specification is a part of a stack of CPE specifications that support a variety of use cases relating to information technology (IT) product description and naming. An individual CPE dictionary is a repository of IT product names, with each name in the repository identifying a unique class of IT product in the world. This specification defines the semantics of the CPE Dictionary data model and the rules associated with CPE dictionary creation and management. This report also defines and explains the requirements that IT products and services, including CPE dictionaries, must meet for conformance with the CPE Dictionary version 2.3 specification.