formerly ICBN or the International Code of Botanical Nomenclature (current version the Shenzhen Code)
Chapter F of this Code covers sections pertaining only to Fungi and can be further revised by the Fungal Nomenclature Session of an International Mycological Congress (IMC). Chapter F was revised as a result of decisions approved on 21 July 2018 by the closing plenary session of the 11th IMC, held in San Juan, Puerto Rico. The resulting San Juan Chapter F was published in the journal IMA Fungus on 27 December 2019 as an open-access article. The San Juan Chapter F supersedes Chapter F of the Shenzhen Code.
heterotypic synonym (botany): (or taxonomic synonym) a synonym that comes into being when a taxon is reduced in status ("reduced to synonymy") and becomes part of a different taxon; the zoological equivalent is "subjective synonym"
subjective synonym (zoology): see taxonomic synonym
taxonomic synonym (botany): see taxonomic synonym
basionym or basyonym (botany), or protonym or original combination (zoology): original name on which the current name is based; in bacteriology "basonym"
combinatio nova (comb. nov.): new combination; when a taxon has been given a new name, preserving one of the previous components
status novus (abbr. stat. nov.): new status; when a taxon has been given a new rank
homonym: names spelled identically, but, in some codes, names spelled similarly, as defined by the code
senior homonym (zoology): the first legitimate use of the name which generally takes priority
junior homonym (zoology), later homonym (botany): a later and generally illegitimate use, though in some circumstances the later name is allowed to stand
hemihomonym: a homonym across naming authorities that is permitted because any confusion is improbable
parahomonym: names that are similar enough to be likely to be confused
isonym (botany) an identical name based on the same type, but published later
ichnotaxon (ichnogenus (igen.), ichnospecies (isp.), etc.): a taxon (genus, species, etc.) only known by its work, e.g. footprints, nests, or bite marks
ootaxon (oospecies, etc.): a taxon known from fossil eggs
sciotaxon a taxon known from partial evidence but believed to be identical to an orthotaxon
circumscription: the limits of a taxon as made evident by its recognized constituency; a taxon may accordingly be circumscribed differently by different authorities if they recognize different constituents
sensu ("sense" in Latin): as in sensu stricto (s. s.) (in the strict sense), sensu lato (in a broad sense), etc.; see sensu for more variants and details
secundum ("following" in Latin): e. g. "secundum Smith"
The main ranks are kingdom (regnum), phylum or division (divisio), class (classis), order (ordo), family (familia), genus and species. The ranks of section and series are also used in botany for groups within genera, while section is used in zoology for a division of an order. Further levels in the hierarchy can be made by the addition of prefixes such as sub-, super-, infra-, and so on.
Divisions such as "morph", "form", "variety", "strain", "breed", "cultivar", hybrid (nothospecies) and "landrace" are used to describe various sub-specific groups in different fields.
It is possible for a clade to be unranked, for example Psoroptidia (Yunker, 1955) and the SAR supergroup. Sometimes a rank is described as clade where the traditional hierarchy cannot accommodate them.
Note that in zoology the English descriptions, such as "conserved name", for example, are acceptable and generally used. These descriptions can be classified between accepted names (nom. cons., nom. nov., nom. prot.) and unaccepted combinations for different reasons (nom. err., nom. illeg., nom. nud., nom. rej., nom. supp., nom. van.), with some cases in between regarding the use (nom. dub.: used but not fully accepted; nom. obl.: accepted but not fully used, so it yields precedence to a nom. prot).
Candidatus (Ca.) - a taxon proposed from incomplete information, such as uncultured bacteria known from metagenomics
nomen conservandum (nom. cons.; plural: nomina conservanda) – a conserved name
nomen dubium (nom. dub.; plural: nomina dubia) (zoo. bact. bot.(informal)) – a name of questionable application[1]
nomen ambiguum (plural: nomina ambigua), (bot.) a name that has been used with more than one meaning
nomen confusum (plural: nomina confusa), (bact.) a name based on a mixed bacterial culture
nomen perplexum (plural: nomina perplexa), a name confusingly similar to another name or names
nomen periculosum (plural: nomina periculosa), an name which can lead to dangerous outcomes, through confusion
nomen erratum (nom. err.; plural: nomina errata) - a name given in error
nomen illegitimum (nom. illeg.; plural: nomina illegitima) – an illegitimate name
nomen invalidum (nom. inval.; plural: nomina invalida) – an invalid name
nomen manuscriptum - a name that appears in a manuscript
nomen monstrositatum (nom. monstr.) – a name based on a monstrosity (fasciation, phyllody or similar deformities)
nomen novum (nom. nov.; plural: nomina nova) – a replacement name
nomen nudum (nom. nud.; plural: nomina nuda) – a name published without an accompanying description
nomen oblitum (nom. obl.; plural: nomina oblita) – a name which has been overlooked (literally, forgotten) and is no longer valid
nomen protectum (nom. prot.; plural: nomina protecta) – a name granted protection
nomen rejiciendum (nom. rej.; plural: nomina rejicienda) – a name that has been rejected and cannot be used
nomen suppressum (nom. supp.; plural: nomina suppressa) – a name that has been suppressed and cannot be used
nomen vanum (plural: nomina vana) - not a useful term, has been used to mean either a nomen dubium (see above in this list), or an invalid change in spelling, better called an unjustified emendation[2]
^On the use of the term nomen vanum in taxonomy. John Chorn and Kenneth N. Whetstone. Museum of Natural History, Kansas, Lawrence 66045. Journal of Paleontology vol 52 no. 2, March 1978
