Preface Standards development within the Information Technology sector is harmonized with international standards development. Through the CSA Technical Committee on Information Technology (TCIT), Canadians serve as the SCC Mirror Committee (SMC) on ISO/IEC Joint Technical Committee 1 on Information Technology (ISO/IEC JTC1) for the Standards Council of Canada (SCC), the ISO member body for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of the International Telecommunication Union (ITU), Canada participates in the International Telegraph and Telephone Consultative Committee (ITU-T). For brevity, this Standard will be referred to as \"CAN/CSA-ISO/IEC 19780-1\" throughout. At the time of publication, ISO/IEC 19780-1:2015 is available from ISO and IEC in English only. CSA Group will publish the French version when it becomes available from ISO and IEC. Scope 1.1 Statement of scope This part of ISO/IEC 19780 specifies the Data Model for text-based expressions. It provides a standardized way of isolating and describing textual expressions composed and communicated by collaborative group members. 1.2 Excluded subjects and aspects For the purposes of simplicity, the following media and contexts have been excluded from this part of ISO/IEC 19780. Communication involving media other than text. Contexts and associated requirements in which one or more participants are intended to receive a given expression are identified individually, apart from the collaborative group (e.g. \"whispering\" or \"private messaging\" in chat contexts). Permissions and privacy information associated with individual participants.