International Committee On Taxonomy of Viruses - Principles of Nomenclature

Principles of Nomenclature

The ICTV's essential principles of virus nomenclature are:

• Stability
• To avoid or reject the use of names which might cause error or confusion
• To avoid the unnecessary creation of names

The ICTV's universal virus classification system uses a slightly modified version of the standard biological classification system. It only recognises the taxa order, family, subfamily, genus, and species. When it is uncertain how to classify a species into a genus but its classification in a family is clear, it will be classified as an unassigned species of that family. Many taxa remain unranked. There are also, as of 2005, GenBank sequences assigned to 3,142 "species" which are not accounted for in the ICTV report (due to the way GenBank works, however, the actual number of proper species is probably significantly smaller). The number of unidentified virus sequences is only expected to increase as the rate of virus sequencing increases dramatically.

The ICTV has been strikingly successful in achieving stability, since their inception in 1962. Every genus and family recognized in the 1980s continued to be in use as of 2005, for example.