The ICSP, formerly the International Committee on Systematic Bacteriology (ICSB), is a committee of appointed representatives from the national microbiological societies and co-opted members that oversees the nomenclature of prokaryotes, determines the rules by which prokaryotes are named, as documented in the International Code of Nomenclature of Prokaryotes (ICNP), and supervises the publishing of the International Journal of Systematic and Evolutionary Microbiology (IJSEM). More details of the functions of the ICSP are given in Article 3 of our Statutes. ICSP is a committee under the Bacteriology and Applied Microbiology Division of the International Union of Microbiological Societies (IUMS). The Judicial Commission of the ICSP issues Opinions concerning matters related to the interpretation of the ICNP.

In the 19th century and the first half of the 20th century, bacteriologists followed the provisions of the Botanical Code of Nomenclature, because bacteria had traditionally been considered to be fungi, i.e., the Schizomycetes. However, the methods of study were very different for plants and bacteria. In bacteriology, emphasis was put on cultural characteristics and viable cultures for nomenclatural type material. Type cultures are not permitted under the Botanical Code; therefore, at the First International Congress of Microbiology in Paris in 1930, proposals were made for bacteriology to establish its own Code of Nomenclature. A committee under the guidance of the American bacteriologist R. E. Buchanan began work on this and, at the Second Congress in London in 1936, a draft Code was presented and placed under the aegis of the International Committee for Bacteriological Nomenclature [later, the International Committee on Systematic Bacteriology (ICSB), and now, the ICSP]. Buchanan condensed the provisions for nomenclature into a few broad principles that are still valid today. Editions of the International Code of Nomenclature of Bacteria (ICNB), latterly, the International Code of Nomenclature of Prokaryotes (ICNP), were issued in 1958, 1975, 1990 and 2019. A new edition is due for publication in late 2022.




ICSP Chairman:  Iain Sutcliffe, PhD, Professor of Microbiology

Faculty of Health & Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK


ICSP Executive Secretary:  Aharon Oren, PhD, Professor of Microbial Ecology

Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel

Phone: +972-2-65-84951


Discussion on proposed changes to the ICNP (The Prokaryotic Code)

July 01 – December 31, 2021

Public discussion on proposed draft revisions of the ICNP

As announced previously (Oren et al., Public discussion on a proposed revision of the International Code of Nomenclature of Prokaryotes. Int J Syst Evol Microbiol 2021;71:004918), the Editorial Board-ICNP has compiled proposed revisions of the ICNP for public discussion, which will open on July 1, 2021, to last for six months. The discussion will be conducted on the Slack messaging app, a communication platform ( Those who wish to be registered in the Slack workspace, in order to participate in the discussions, should contact Prof. Aharon Oren (Editor-in-Chief for the ICNP; This email address is being protected from spambots. You need JavaScript enabled to view it.) or Prof. Iain Sutcliffe (ICSP Chair; This email address is being protected from spambots. You need JavaScript enabled to view it.). PDF copies of the sections of the ICNP to be discussed are posted below.


Chapter 1. General Considerations Download PDF


Chapter 2. Principles Download PDF


Chapter 3. Rules of Nomenclature with Recommendations

            Rules 01-09 Download PDF

            Rules 10-17 Download PDF

            Rules 18-22 Download PDF

            Rules 23-29 Download PDF

            Rules 30-39 Download PDF

            Rules 40-49 Download PDF

            Rules 50-59 Download PDF

            Rules 60-65 Download PDF


Chapter 4. Advisory Notes  Download PDF


Appendix 1  Download PDF

Appendix 2  Download PDF

Appendix 3  Download PDF

Appendix 4  Download PDF

Appendix 5  Download PDF

Appendix 6  Download PDF

Appendix 7  Download PDF

Appendix 8  Download PDF

Appendix 9  Download PDF

Appendix 10 Download PDF

Appendix 11 Download PDF

Appendix 12 Download PDF

Appendix 13 Download PDF


Data of members are stored by the ICSP with regard to EU GDPR regulations. Requests to redact or remove information should be sent to the ICSP Website Manager, Edward Moore:  This email address is being protected from spambots. You need JavaScript enabled to view it.