The GBIF Backbone Taxonomy, often called the Nub taxonomy, is a single synthetic management classification with the goal of covering all names GBIF is dealing with. It's the taxonomic backbone that allows GBIF to integrate name based information from different resources, no matter if these are occurrence datasets, species pages, names from nomenclators or external sources like EOL, Genbank or IUCN. This backbone allows taxonomic search, browse and reporting operations across all those resources in a consistent way and to provide means to crosswalk names from one source to another. It is updated regulary through an automated process in which the Catalogue of Life acts as a starting point also providing the complete higher classification above families. The following 56 sources from the have been used to assemble the GBIF backbone: Catalogue of Life (3175925 names); Interim Register of Marine and Nonmarine Genera (733720 names); World Register of Marine Species (333396 names); The Plant List with literature (287022 names); The Paleobiology Database (147044 names); Index Fungorum (137347 names); International Plant Names Index (114127 names); Backbone Family Classification Patch (94826 names); Integrated Taxonomic Information System (ITIS) (69148 names); Artsnavnebasen (33510 names); Plazi.org taxonomic treatments database (32543 names); GRIN Taxonomy (30748 names); The Clements Checklist (19663 names); Dyntaxa - Svensk taxonomisk databas (15173 names); Brazilian Flora Checklist - Brazilian Flora 2020 project - Projeto Flora do Brasil 2020 (13067 names); Mammal Species of the World (6393 names); Official Lists and Indexes of Names in Zoology (5790 names); International Cichorieae Network (ICN): Cichorieae Portal (5032 names); Orthoptera Species File (4826 names); Catalogue of Afrotropical Bees (4640 names); Database of Vascular Plants of Canada (VASCAN) (4323 names); Prokaryotic Nomenclature Up-to-date (4151 names); Taxon list of fungi and fungal-like organisms from Germany compiled by the DGfM (4034 names); IOC World Bird List, v6.3 (3830 names); Checklist of Beetles (Coleoptera) of Canada and Alaska. Second Edition. (3378 names); Aphid Species File (2232 names); Cockroach Species File (1151 names); Taxon list of vascular plants from Bavaria, Germany compiled in the context of the BFL project (909 names); GBIF Algae Classification (885 names); Mantodea Species File (608 names); ION Taxonomic Hierarchy (572 names); Coreoidea Species File (498 names); Taxon list of Jurassic Pisces of the Tethys Palaeo-Environment compiled at the SNSB-JME (444 names); Taxon list of animals with German names (worldwide) compiled at the SMNS (349 names); Phasmida Species File (294 names); Plecoptera Species File (261 names); Psocodea Species File (197 names); Dermaptera Species File (152 names); GBIF Backbone Patch (115 names); Coleorrhyncha Species File (104 names); Grylloblattodea Species File (51 names); Taxon list of mosses from Germany compiled in the context of the GBOL project (48 names); Embioptera Species File (38 names); True Fruit Flies (Diptera, Tephritidae) of the Afrotropical Region (36 names); Chrysididae Species File (15 names); Taxon list of liverworts from Germany compiled in the context of the GBOL project (10 names); GBIF Backbone Taxonomy (9 names); Taxon list of Diplopoda from Germany in the context of the GBOL project (9 names); Taxon list of Pauropoda from Germany compiled in the context of the GBOL project (8 names); TAXREF (7 names); Taxon list of Pisces and Cyclostoma from Germany compiled in the context of the GBOL project (7 names); Taxon list of Pteridophyta from Germany compiled in the context of the GBOL project (6 names); Mantophasmatodea Species File (1 names); Taxon list of hornworts from Germany compiled in the context of the GBOL project (1 names);