This part of ISO/IEC 21000 specifies the syntax and semantics of a Rights Expression Language.This part of ISO/IEC 21000 does not give any permission, including permissions about who is legally or technically allowed to create Rights Expressions. It does not specify the security measures of trusted systems, propose specific applications, or describe the details of the systems required for accounting (monetarytransactions, state transactions, and so on). It also does not specify if or when Rights Expressions shall be consulted.However, this part of ISO/IEC 21000 does define an authorization model to specify whether the semantics of a set of Rights Expressions permit a given Principal to perform a given Right upon a given optional Resource during a given time interval based on a given authorization context and a given trust root.Clause 1 gives the scope of this part of ISO/IEC 21000. Clause 2 gives the normative references. Clause 3 gives pertinent terms, definitions, symbols, and abbreviated terms. Clause 4 gives the namespaces and conventions. Clause 5 specifies the authorization model. Clause 6 defines architectural concepts. Clause 7specifies the syntax and semantics integral to the architecture. Clause 8 specifies syntax and semantics peripheral to the architecture but still useful in many domains beyond multimedia. Clause 9 specifies syntax and semantics specific to multimedia. Annex A uses W3C XML Schema to normatively specify the syntax of the types and elements defined throughout this part of ISO/IEC 21000. Annex B normatively defines QualifiedNames for identifying countries, regions, and currencies. Annex C gives an informative simplified equality algorithm. Annex D gives some example Rights Expressions. Annex E describes the design philosophy for extensions and profiles of this part of ISO/IEC 21000. Annex F demonstrates how to introduce new rights as an extension to this part of ISO/IEC 21000. Annex G gives an example profile of this part of ISO/IEC 21000.Annex H describes the relationship between ISO/IEC 21000-6 and this part of ISO/IEC 21000. Annex I describes the relationship between ISO/IEC 21000-2 and this part of ISO/IEC 21000. Annex J describes an example revocation mechanism and gives a walk-through of revocation.