Alcance
ISO/IEC 21000-20:2016 specifies a language for representing contracts in the Multimedia Framework formed for the transaction of MPEG-21 Digital Items or services related to the MPEG-21 Framework.Contract Expression Language (CEL) aims at digitally representing the agreements made in environments using ISO/IEC 21000. These agreements are contracts for transactions of content packed as Digital Items, as well as services provided around this content.The range of contracts under scope are as follows:- contracts about transactions on rights for the exploitation of content as MPEG-21 Digital Items;- contracts about the provision of MPEG-21-based services, i.e. delivery, identification, encryption, search and others.The aspects represented by CEL contracts include the following:- the textual clauses, in natural language as they are in the narrative contract, duly structured;- the operative clauses, as computer language expressions.