Information Technology — an Operational Model for Characters and Glyphs Annex E: Examples of Character-to-glyph Mapping ............................... 22

iii Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental , in liaison with ISO and IEC, also take part in the work. The main task of a technical committee is to prepare International Standards, but in exceptional circumstances a technical committee may propose the publication of a Technical Report of one of the following types: ² type 1, when the required support cannot be obtained for the publication of an International Standard, despite repeated efforts; ² type 2, when the subject is still under technical development or where for any other reason there is the future but not immediate possibility of an agreement on an International Standard; ² type 3, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (" state of the art " , for example). Technical Reports of types 1 and 2 are subject to review within three years of publication to decide whether they can be transformed into International Standards. Technical Reports of type 3 do not necessarily have to be reviewed until the data they provide are considered to be no longer valid or useful. ISO/IEC TR 15285, which is a Technical Report of type 3, was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 2, Coded character sets and Subcommittee SC 18, Document processing and related communication (which has since been reorganized into SC 33, Distributed application services).