There is no official classification of prokaryotes, but the names given to prokaryotes are regulated. The International Code of Nomenclature of Bacteria (Bacteriological Code) and its successors contain General Considerations, Principles, Rules and Recommendations which govern the way in which the names of prokaryotes are to be used. The last revision of the Code is the cornerstone of prokaryotic nomenclature.
In 1975, the Bacteriological Code (1975 Revision) introduced a new concept, that of the valid publication of names of prokaryotes. The publication of the Approved Lists of Bacterial Names was part of this concept, and set a new starting point in prokaryotic nomenclature. The International Code of Nomenclature of Bacteria (1990 Revision) states that the name of a taxon is validly published, and therefore has standing in nomenclature, if one among a few number of criteria is met.
In addition to valid publication of a name, the Bacteriological Code (1990 Revision) and its successors also state that only correct names are to be used, i.e. based on valid publication, legitimacy, and priority of publication (Principle 6).
A special aspect of nomenclature is the correct formation of names according to the orthographical rules of Latin or Greek.
While there no official classification of bacteria [1], there is an official nomenclature, i.e. there are names validly published as a result of conformity with the Rules of Nomenclature. "Many microbiologists are not particularly interested in nomenclature and are unaware of or indifferent to the problem they sometimes create" [2]. However, nomenclature is a vital component of systematic bacteriology and it is neither esoteric nor absurd.
The Bacteriological Code (1990 Revision) and its most recent successor, which is the cornerstone of prokaryotic nomenclature, are not always easy to use. In fact, the formal system of naming bacteria appears sometimes tiresome, confusing and even exasperating to the working bacteriologist [3]. Accordingly, some bacteriologists are not aware of the Rules. A variety of resources are provided which assist in reading and comprehending this "List of Prokaryotic Names with Standing in Nomenclature".
  1. SNEATH (P.H.A.) and BRENNER (D.J.): "Official" nomenclature lists. ASM News, 1992, 58, 175.
  2. GIBBONS (N.E.): Reference collections of bacteria. - The need and requirements for type and neotype strains. In: R.E. BUCHANAN and N.E. GIBBONS (editors), Bergey’s Manual of Determinative Bacteriology, eighth edition, The Williams & Wilkins Company, Baltimore, 1974, p. 14-17.
  3. BOUSFIELD (I.J.): Bacterial nomenclature and its role in systematics. In: M. GOODFELLOW and A.G. O’DONNELL (editors), Handbook of new bacterial systematics, Academic Press, London, 1993, p. 317-338.


Information on nomenclature available at LPSN:
The notes on the pages for the individual taxon names also included many hints on nomenclatural topics. The taxon pages refer to LPSN glossary for clarifying a variety of issues; aspects of nomenclature are among them.
Some papers about nomenclature freely available in IJSEM (papers cited in chronological order):

Discontinued pages

The collections of internet links found in the previous versions of LPSN may not be continued as such but the content distributed over pages dedicated to specific topics. Please see the archived version.
Some of the ancient LPSN pages on nomenclature are not going to be moved to the new system. The contained information is either outdated or available via the general search page. The archived versions of these pages are found here: