IRMNG contains scientific names (only) of the
genera (plus zoological subgenera, see below), a subset of
species, and principal higher ranks of most plants, animals and other
kingdoms, both living and extinct, within a standardized taxonomic hierarchy, with associated machine-readable information on habitat (e.g.
marine/nonmarine) and
extant/
fossil status for the majority of entries. The database aspires to provide complete coverage of both accepted and unaccepted genus names across all kingdoms, with a subset only of species names included as a secondary activity. The names in IRMNG fall within the governance of the
International Code of Zoological Nomenclature for zoology (covering animals, zoological protists, and trace fossils attributable to the activities of animals), the
International Code of Nomenclature for algae, fungi, and plants (ICN or ICNafp) for botany including those groups, the
International Code of Nomenclature of Prokaryotes for
Bacteria and
Archaea, and the
International Committee on Taxonomy of Viruses for that group. In its July 2024 release, IRMNG contained 508,851 genus names, of which 240,625 were listed as "accepted", 123,117 "unaccepted", 23,192 of "other" status i.e. interim unpublished,
nomen dubium,
nomen nudum,
taxon inquirendum or temporary name, and 121,917 as "uncertain" (unassessed for taxonomic status at this time). The data originate from a range of (frequently domain-specific) print, online and database sources, including (among others)
Nomenclator Zoologicus for animals and
Index Nominum Genericorum for plants, and are reorganised into a common
data structure to support a variety of online queries, generation of individual taxon pages, and bulk data supply to other
biodiversity informatics projects. IRMNG content can be queried and displayed freely via the web, and download files of the data down to the taxonomic rank of genus as at specific dates are available in the
Darwin Core Archive (DwC-A) format. The data include
homonyms (with their authorities), including both available (validly published) and selected unavailable names. Since in zoology (only) names of subgenera are included, along with genera, in the "genus-group" and are deemed by the "principle of coordination" to have been simultaneously published at both ranks even if not explicitly so at the time of original publication, they are included as available generic names in the IRMNG compilation but marked as "unaccepted names" (not currently used as the accepted name for a genus) unless where they are currently in use as the accepted name for a genus. By contrast, the botanical Code (ICN), which covers Algae, Fungi and Plants, lacks such a provision, so subgenera published under that Code are not included in IRMNG except where they have been explicitly re-ranked to be botanical genera, in which case a new "name" is considered to have been created at that point with authorship given in the form of the original author(s) of the subgenus in parentheses, followed by the name of the author(s) responsible for the newly elevated status. Estimates for "accepted names" as held at May 2023 are as follows, broken down by kingdom, following the methodology used in Rees et al., 2020 (updated using 2023 data): •
Animalia: 189,287 accepted genus names plus notional 50% of 104,583 "uncertain" names: est. total 241,578 accepted genera •
Plantae: 25,394 accepted genus names plus notional 50% of 13,838 "uncertain" names: est. total 32,313 accepted genera •
Fungi: 10,702 accepted genus names plus notional 50% of 358 "uncertain" names: est. total 10,881 accepted genera •
Chromista: 9,912 accepted genus names plus notional 50% of 2,379 "uncertain" names: est. total 11,102 accepted genera •
Protozoa: 999 accepted genus names plus notional 50% of 2,164 "uncertain" names: est. total 2,081 accepted genera •
Bacteria: 3,337 accepted genus names plus notional 50% of 223 "uncertain" names: est. total 3,393 accepted genera •
Archaea: 140 accepted genus names (no "uncertain" genera) •
Viruses: 851 accepted genus names (no "uncertain" genera) ==Database location and hosting==