The current grouping is:* Volume 1 (2001): The Archaea and the deeply branching and phototrophic Bacteria* Volume 2 (2005): The Proteobacteria—divided into three books:** 2A: Introductory essays** 2B: The Gammaproteobacteria** 2C: Other classes of Proteobacteria* Volume 3 (2009): The Firmicutes* Volume 4 (2011): The Bacteroidetes, Spirochaetes, Tenericutes (Mollicutes), Acidobacteria, Fibrobacteres, Fusobacteria, Dictyoglomi, Gemmatimonadetes, Lentisphaerae, Verrucomicrobia, Chlamydiae, and Planctomycetes* Volume 5 (in two parts) (2012): The Actinobacteria==Critical reception==The "Annals of Internal Medicine" described the volumes as "clearly written, precise, and easy to read" and "particularly designed for those interested in taxonomy.
Последнее издание справочника состоит из 5 томов:* Том I (2001): «The Archaea and the deeply branching and phototrophic Bacteria»* Том II (2005): «The Proteobacteria» — в трёх книгах:** IIA: «Introductory essays»** IIB: «The Gammaproteobacteria»** IIC: Other classes of Proteobacteria* Том III (2009): «The Firmicutes»* Том IV (2010): «The Bacteroidetes, Spirochaetes, (Mollicutes), , , Fusobacteria, Dictyoglomi, Gemmatimonadetes, , Verrucomicrobia, , and Planctomycetes»* Том V (2011): «The Actinobacteria»Журнал описывает справочник как «ясно написанный, точный, легко читаемый» и «созданный специально для интересующихся таксономией».