The PhyloCode is a formal set of rules governing phylogenetic nomenclature. It is designed to name the parts of the tree of life by explicit reference to phylogeny. The PhyloCode will go into operation in a few years, but the exact date has not yet been determined. It is designed so that it may be used concurrently with the existing codes based on rank-based nomenclature (ICBN, ICZN, etc.). We anticipate that many people whose research concerns phylogeny will find phylogenetic nomenclature advantageous.

The version of the PhyloCode that is posted here is a draft. Some parts of it may change before the code is implemented. Comments are welcome and may be sent to phylocode@ohio.edu. A new version (5), which differs substantially from the one posted here (4c), was approved by the Committee on Phylogenetic Nomenclature in January 2014. It will be posted here once the Preface and Index have been completed. In the meanwhile, a beta version is available on request from Phil Cantino (cantino@ohio.edu).

The PhyloCode grew out of a workshop at Harvard University in August 1998, where decisions were made about its scope and content. Many of the workshop participants, together with several other people who subsequently joined the project, served as an advisory group (see the PhyloCode preface for a list of the people involved). In April 2000, a draft was made public on this web site and comments were solicited from the scientific community. All comments were forwarded to the advisory group, and many of them elicited discussion. A second workshop was held at Yale University in July 2002, at which the discussion focused on the governance of species names and the publication of a book of phylogenetically defined clade names as a companion to the PhyloCode (see the History section of the Preface).

The First International Phylogenetic Nomenclature Meeting, which took place July 6–9, 2004 in Paris, was attended by about 70 systematic and evolutionary biologists from 11 nations. The program can be downloaded from the "Events" page. This was the first open, multi-day conference that focused entirely on phylogenetic nomenclature, and it provided the venue for the inauguration of the International Society for Phylogenetic Nomenclature (ISPN). The ISPN membership elects the Committee on Phylogenetic Nomenclature (CPN), the responsibilities of which are explained in Art. 22 of the PhyloCode. The CPN has taken over the role of the advisory group that oversaw the earlier stages of development of the PhyloCode.

The Third International Phylogenetic Nomenclature Meeting was held July 21–23, 2008 at Dalhousie University, Halifax. More information can be downloaded from the "Events" page.

The International Society for Phylogenetic Nomenclature is open to all. More information about the ISPN and a membership form can be found at http://phylonames.org.

Changes in Version 4. The current version of the PhyloCode (version 4c), which was posted in January 2010, differs from version 4b in many minor ways, which are detailed in the Preface. In contrast, version 4b (posted in September 2007) differs in major ways from version 3. See the "Changes in Version 4" section of the Preface for details.

If you would like to join an internet discussion group focusing on phylogenetic nomenclature, go to http://listserv.ohio.edu/mailman/listinfo/phylocode/ and follow the directions to subscribe.

We are grateful to Richard Piccard, Web Resources Manager in the Office of Information Technology at Ohio University, for technical support.