Interdivisional Committee on Terminology, Nomenclature and Symbols


This is a core activity in the area in which IUPAC is recognized as the world authority on chemical nomenclature, terminology, standardized methods for measurements, atomic weights, etc. Since January 2002, this Committee supersedes the Inter-divisional Committee on Nomenclature and Symbols (IDCNS).

See Q&As on IUPAC Standards and Recommendations, by Ron Weir, Chem Int Apr 2017, pp. 34-35;

Terms of Reference

(i) To be responsible for submission to the Bureau/Council, in accordance with Bylaw 2.11, for publication or otherwise, any IUPAC document concerned with terminology, nomenclature, symbols and other conventions. “Document” includes books emanating from Divisional activities and sponsored by IUPAC for publication.
(ii) Before recommending any material for publication as an IUPAC document, to ensure that full consultations have taken place, and the widest possible consensus has been reached among all Divisions and other bodies of the Union, and between IUPAC and other ICSU bodies, the international standardizing organizations, and Conference Generale des Poids et Mesures (CGPM) and its Committees.
(iii) To ensure, via each Division’s Titular Member on ICTNS, that all documents for publication emanating from that Division have been subject to a satisfactory level of review of substantive material by the Division Committee.
(iv) To ensure that any considered IUPAC view shall carry the fullest possible weight among other international organizations, all negotiations on matters concerned with nomenclature and symbols with other ICSU bodies, with the international standardizing organizations, and with CGPM and its Committees, shall be conducted through ICTNS, which shall advise the Executive Committee accordingly.
(v) To be responsible, after consultation with all relevant bodies of IUPAC, for the official IUPAC comments on all documents on nomenclature, symbols, terminology and conventions sent to the Union for comment.
(vi) To advise the President and the Executive Committee on suitable persons for appointment as representatives of IUPAC on other bodies concerned with nomenclature, symbols and terminology.

Composition and Terms of Office

(i) There shall be a standing Interdivisional Committee on Terminology, Nomenclature and Symbols, composed of a Chair, a Secretary, up to three Titular Members and up to three Associate Members as a “core” membership and one Titular Member from each Division.
(ii) The President, in consultation with the Executive Committee, shall appoint the Titular Members and the Associate Members. ICTNS and the Division Presidents may propose names of persons suitably qualified for appointment.
(iii) The period of service of the core Titular Members and Associate Members shall be four years, renewable for a further term of four years. The period of service for Titular Members from the Divisions shall be two years, renewable up to a total of eight years.
(iv) The President, in consultation with the Executive Committee, shall appoint the Chair and the Secretary. ICTNS may propose candidates.
(v) The period of service of the Chair and of the Secretary shall be four years, renewable for a further term of four years. The sum of the years of service as a Titular Member or as an Associate Member and as the Chair or the Secretary shall not exceed ten years.
(vi) The following organizations shall be invited to attend meetings of ICTNS:
Bureau International des Poids et Mesures
International Organization for Standardization
International Union of Biochemistry and Molecular Biology
International Union of Crystallography
International Union of Nutritional Sciences
International Union of Pharmacology
International Union of Pure and Applied Physics

Subcommittees and Commissions

Current Projects

Meeting Minutes

• Istanbul, Turkey, 11-12 Aug 2013 (pdf file – 196KB)
• Lisbon, Portugal, 5-6 May 2012 (pdf file – 168KB)
• San Juan, Puerto Rico, 31 July – 1 Aug 2011 (pdf file – 2.2MB); attachments (pdf file – 8.49MB)
• Glasgow, UK, 2-3 Aug 2009 (pdf file – 382KB); + other reports (pdf file – 1.32MB)
• Torino, Italy, 7-8 Aug 2007 (pdf file – 189KB); agenda (pdf file – 1.25MB) + other reports (pdf file – 473KB)
• Beijing, China, 16-17 Aug 2005 (pdf file – 267KB); attachments (pdf file – 1.85MB)

Activity Reports

Relevant Documents and Links
Procedure for Publication of IUPAC Technical Reports and Recommendations
Guidelines for Drafting IUPAC Technical Reports and Recommendations (also in IUPAC Handbook 2004-2005)

Sections of the Guidelines have been more recently revised and published separately in Chem Int; these include:

On the Use of Italic and Roman Fonts for Symbols in Scientific Text. I.M. Mills, Chem Int. Sep 2014, pp.23-24;
(The original 1999 version has been prepared by I.M. Mills and W.V. Metanomski; see PDF)

On the Use of Quantity calculus (T. Cvitas) March 2015, p. 26;

The Units ppm, ppb, and ppt ((I. Mills) March 2014, p. 23;

Other useful doc and links:
A Concise Summary of Quantities, Units and Symbols in Physical Chemistry, prepared for publication by J. Stohner and M. Quack, IUPAC Commission on Physicochemical Symbols, Terminology and Units, 2009, see Chem Int July 2011, 4-page centerfold supplement. A laminated version is available from the Royal Society of Chemistry at

Best estimates of the values of the fundamental constants, published by CODATA and available on the National Institute of Standards and Technology (NIST) website

Use of Abbreviations in the Chemical Literature, prepared for publication by David R. Lide, Jr., Pure Appl. Chem., 1980, Vol. 52, No. 9, pp. 2229-2232; (or PDF)