Valid publication of the name of a taxon (including a new combination) requires publication in the International Journal of Systematic Bacteriology (IJSB) of (a) the name of the taxon, (b) for new taxa the designation of a type, and (c) a description or a reference to an effectively published description of the taxon whether in the International Journal of Systematic Bacteriology or in another publication. Fuller details are given below.

1. The name should be in the correct form. Generic and suprageneric names are single words in Latin form and spelled with an initial capital letter. Names of species are binary combinations of words in Latin form consisting of a generic name and a single, specific epithet, the latter spelled with an initial lowercase letter. Subspecific names are ternary combinations consisting of the name of a species followed by the term "subspecies" (ordinarily "subsp.") and this in turn by a single subspecific epithet. Names of taxa from the rank of order to tribe inclusive are formed by the addition of the appropriate suffix to the stem of the name of the type genus (see 5 below). The suffix for order is -ales, for suborder -ineae, for family -aceae, for subfamily -oideae, for tribe -eae, and for subtribe -inae.
   Although not a requirement for the valid publication of a new name, the derivation of the name should be given.
   Where possible, the title of the paper should include any new names or combinations that are proposed in the text.
2. The name should be clearly proposed as a new name or combination and should be accepted by the author at the time of publication. New names are ordinarily proposed by an author appending the phrase "species nova" (abbreviation: sp. nov.), "genus novum" (abbreviation: gen. nov.), "combinatio nova" (abbreviation: comb, nov.), or the like after the name or combination that is being proposed as new; alternatively, the author may make a statement to the effect that a new name or combination is being introduced. Revival of names published prior to 1 January 1980 but not included in an Approved List may be effected by provisions in Rule 33; advice on this is also provided in a report by the Chairman of the Judicial Commission (IJSB [1981] 31:678).
3. The name should not be a later homonym of a previously validly published name of an alga, bacterium, fungus, protozoon, or virus. (See the IJSB from 1975 onward and Appendices 2 and 3 for published sources of names of bacterial, algal, protozoal, fungal, and viral taxa.)
4. The name must be accompanied by a description of the taxon or by a reference to a previously published description of the taxon (see 6 below).
5. The nomenclatural type of a new taxon should be designated. In the case of species and subspecies which can be cultivated, the type strain should be described by itself and should be designated by the author's strain number as well as the accession number under which it is held by at least one culture collection from which cultures of the strain are available.
   A nomenclatural type is that constituent element of a taxon to which the name of a taxon is permanently attached. The type of a species or a subspecies is a strain, that of a genus is a species, and that of an order, family, subfamily, tribe, or subtribe is the genus on whose name the name of the higher taxon is based (see 1 above). The type of a taxon above the rank of order is one of the contained orders. For species and subspecies whose cells cannot be maintained in culture or for which cultures are not maintained, the type strain can be represented by the original description and by illustrations and specimens.
   A type strain is one of the strains on which the author who first described a named organism based the description of the organism and which the author, or a subsequent author, definitely designated as a type.
   A neotype strain replaces a type strain which can no longer be found. The neotype should possess the characteristics as given in the original description; any deviations should be explained. A neotype strain must be proposed by an author in the IJSB (proposed neotype) together with a reference (or references) to the first description and name for the microorganism (or to an Approved List if appropriate), a description (or reference to a description) of the proposed neotype strain, and a record of the author's designation for the type strain and of at least one culture collection from which cultures of the strain are available. The neotype strain becomes established two years after the date of publication in the IJSB (established neotype). Any objections should be referred to the Judicial Commission within the first year after publication of the proposal. A neotype strain shall be proposed only after a careful search for original strains. If an original strain is subsequently discovered, the matter shall be referred immediately to the Judicial Commission. Allowance is made for replacement of an unsuitable type strain.
6. Descriptions of taxa should include the following information: (a) those characteristics which are essential for membership in the taxon, i.e., those characteristics which constitute the basic concept of the taxon; (b) those characteristics which qualify the taxon for membership in the next higher taxon; (c) the diagnostic characteristics, i.e., those characteristics which distinguish the taxon from closely related taxa; and (d) in the case of species, the total number of strains studied, the strain designations, and the number of strains which are either positive or negative for each characteristic. If the strains are not homogeneous in a characteristic, the specific strain numbers for those strains which disagree with the majority should be given. From this information, the detailed results for each strain can be reconstructed without the full publication of the details for each strain. Where appropriate, suitable photomicrographs and, if necessary, electron photomicrographs should be included as part of the description to show morphological or anatomical characters that are pertinent to the classification. Descriptions should conform at least to such minimal descriptions as have been approved (see Appendix 6).