Table 1.

Application of taxonomic nomenclature

Incorrect usage	Correct usage	Explanation
Characterization of Measles virus Characterization of the Measles virus Characterization of measles virus	Characterization of measles virus	Species is a taxon. Taxa are ideas and do not exist physically. Taxa are italicized and capitalized. Taxa cannot be discovered or characterized, they can only be created. Taxa refer to theoretical averages of groups of viruses; hence taxa are not preceded by articles. Viruses do exist physically and can be discovered and described. Virus names are not italicized and not capitalized
A new arenavirus species, Machupo virus, was discovered in Bolivia A new arenavirus species, Machupo virus, was discovered in Bolivia	A new arenavirus, Machupo virus, was discovered in Bolivia and required the creation of a new species (Machupo virus)	See above. Taxa cannot be discovered, they can only be established. Species are italicized, viruses are not
The Kyasanur Forest disease virus is virulent in Bonnet macaques	Kyasanur Forest disease virus(es) is/are virulent in Bonnet macaques. The 63696 variant of Kyasanur Forest disease virus (KFDV-63696) is virulent in Bonnet macaques	There are many different Kyasanur Forest disease viruses (isolates, variants, and possibly strains). Even if they haven't been described yet we can be certain that they exist. Kyasanur Forest disease virus(es) is not italicized because the sentence refers to the actual virus(es) and not to the species Kyasanur Forest disease virus. Definite articles refer to definite entities, i.e. individual isolates, variants or strains
Nidovirales possess a positive-stranded RNA genome with a particular gene order	Nidovirads are (defined as) viruses with a positive-stranded RNA genome with a particular gene order	Nidoviruses, or more precisely nidovirads, is the vernacular name for all members of the order Nidovirales. Since taxa such as orders are concepts they cannot have (possess) physical properties
The families Comoviridae, Dicistroviridae, Marnaviridae, Picornaviridae, and Sequiviridae, and the genera Cheravirus, Iflavirus, and Sadwavirus are members of the order Picornavirales	The families Comoviridae, Dicistroviridae, Marnaviridae, Picornaviridae, and Sequiviridae, and the genera Cheravirus, Iflavirus, and Sadwavirus are members of the order Picornavirales Comovirids, dicistrovirids, marnavirids, picornavirids, and sequivirds, and cheraviruses, iflaviruses, and sadwaviruses are members of the order Picornavirales Comovirids, dicistrovirids, marnavirids, picornavirids, and sequivirds, and cheraviruses, iflaviruses, and sadwaviruses are picornavirads	Families and genera are taxa (ideas) and have to be italicized, except when their vernacular names are used