Scientific nomenclature
The creation of names for the individual taxa (or animals only from the level of a subspecies to the level of a superfamily) has fixed formalized rules. Some of them are binding, while others have only the character of recommendations. The international rules of zoological and biological nomenclature used in the systematics of fungi, bacteria and viruses differ in certain details.
Each species has a two-word, generally Latin or Latinized name consisting of the name of the genus to which it belongs and the name of the species. The names of higher taxa consist of a single word, while the names of species in a genus that contains subgenera have three words, where the name of the subgenus is placed in round brackets between the name of the genus and the name of the species. The names of the genus, subgenus and species are written in text in italics; the names of the genus and subgenus and also the names of higher taxa start with a capital letter and the second part of the name of the species starts with a small letter. The name of the author and the year in which the species was described should, and in taxonomic articles must, be written after the name. If the particular author originally described the species under a different genus name, the name of this author and the year of description are enclosed in round brackets. If a species was described and named independently by several authors, the name under which the species was first described takes precedence; however, this priority principle does not apply to descriptions published prior to a certain date; for example for the vast majority of animals, it does not apply to descriptions published in the pre-Linnean period, i.e. prior to 1758. In especially justified cases, the continuity principle can be given preference; if a younger synonym is generally known and broadly used and return to the formally more correct name would lead to chaos in the professional literature, the international nomenclature commission may approve the use of a younger name.
The type principle continues to be employed in taxonomy. Where possible, the species names are connected with a certain type specimen. If it is discovered that the type specimen belongs to some other species than the author of the description originally thought, or if the original species is divided into several separate species, the original name is applied to the species to which this type specimen belongs. The names of higher taxa have a single word and are again bound to the name of an internal taxon at a higher level – a type taxon. Thus, a type taxon of a certain genus is a certain species and a type taxon of a certain family is a certain genus. The names of taxa at the individual levels (for example only at the superfamily level in a zoological system) have specific suffixes according to which it is possible to determine the level to which the taxon belongs; however, these suffixes differ in the botanical and zoological literature. The system of laws in international nomenclature is, of course, far more extensive and complicated and attempts to cover all the situations that could occur and that could endanger the unambiguity and continuity of the scientific names employed in the taxonomic system.