The Ideographic Research Group (IRG), formerly called the Ideographic Rapporteur Group, is a subgroup of the ISO/IEC Joint Technical Committee, responsible for developing aspects of The Unicode Standard pertaining to CJK unified ideographs.The IRG is composed of representatives from the Unicode Consortium, as well as experts from China, Japan, South Korea, Vietnam, and other regions that have historically used Chinese characters, as well as experts. The group holds two meetings every year lasting 4-5 days each, subsequently reporting its activities to its parent ISO/IEC JTC 1/SC 2 (WG2) committee.
The precursor to the IRG was the CJK Joint Research Group (CJK-JRG), established in 1990. In October 1993, this group was re-established with its present initials as a subgroup of WG2. In June 2019, the subgroup acquired its current name.
The IRG rapporteur from 1993 to 2004 was Zhang Zhoucai (张轴材), who had been convenor and chief editor of CJK-JRG from 1990 to 1993. Since 2004, the IRG rapporteur has been Hong Kong Polytechnic University professor Lu Qin (陸勤) In June 2018, the title of "rapporteur" was changed to "convenor".
The IRG is responsible for reviewing proposals to add new CJK unified ideographs to the Universal Multiple-Octet Coded Character Set (ISO/IEC 10646), and equivalently the Unicode Standard, and submitting consolidated proposals for sets of unified ideographs to WG2, which are then processed for encoding in the respective standards by SC2 and the Unicode Technical Committee. National and liaison bodies represented in IRG include China, Hong Kong and Macau, Japan, North and South Korea, Singapore, the Taipei Computer Association as representatives on Taiwan, the United Kingdom, Vietnam, and the Unicode Consortium.
- CJK Unified Ideographs and CJK Compatibility Ideographs (version 1.0)
- CJK Unified Ideographs Extension A (version 3.0)
- CJK Unified Ideographs Extension B and CJK Compatibility Ideographs Supplement (version 3.1)
- CJK Unified Ideographs Extension C (version 5.2)
- CJK Unified Ideographs Extension D (version 6.0)
- CJK Unified Ideographs Extension E (version 8.0)
- CJK Unified Ideographs Extension F (version 10.0)
- CJK Unified Ideographs Extension G (version 13.0)
- CJK Unified Ideographs Extension H (version 15.0)
Since 2015, proposed characters submitted by IRG member bodies have been processed in batches called "IRG Working Sets". Each working set undergoes several years of review by IRG experts before official submission of the working set to WG2 as a new block. Once accepted by WG2, the proposed block is processed according to the individual procedures followed by ISO/IEC JTC1 SC2 and the Unicode Technical Committee (UTC). In the case of SC2, this involves balloting of ISO member bodies. The following working sets have been processed by IRG:
- WS2015 became CJK Unified Ideographs Extension G (version 13.0)
- WS2017 became CJK Unified Ideographs Extension H (version 15.0)
- WS2021 may become CJK Unified Ideographs Extension J in a future version.
- "ISO/IEC JTC1/SC2/WG2/IRG: Ideographic Rapporteur Group".
- "Resolutions of the 24th ISO/IEC JTC 1/SC 2 Plenary Meeting, Redmond, WA, US, 2019-06-17 and 21". ISO/IEC JTC 1/SC 2. 24 June 2019. Retrieved 24 June 2019.
- The Unicode Consortium (2021). "Han Unification History: Ideographic Rapporteur Group". The Unicode Standard, Version 14.0.0 (PDF). The Unicode Consortium. p. 987. ISBN 978-1-936213-29-0.
- "LU, Qin(Lu Chin)". Retrieved 24 June 2019.
- "Resolutions of the 23rd ISO/IEC JTC 1/SC 2 Plenary Meeting, London, UK, 2018-06-18, 22". ISO/IEC JTC 1/SC 2. 28 June 2018. Retrieved 24 June 2019.
- "Unicode Standard Annex #45: U-source Ideographs". The Unicode Standard. Unicode Consortium.
- "Appendix E: Han Unification History" (PDF). The Unicode Standard. Unicode Consortium. September 2021.
- "Ideographic Rapporteur Group". Office of the Government Chief Information Officer.
- "FAQ - Chinese and Japanese".
- IRG homepage, including meeting documents and Working Set revisions