Several types of data records are contained in GRIN TAXONOMY. These include accepted or synonymic scientific names, common names, distributions, literature references, and economic impacts. Each of these is discussed below, and the number of records currently in GRIN relating to each type is indicated.

Accepted name records are searchable at the level of family and genus or species and infraspecies. The generic records include a complete listing of the 14,118 accepted spermatophyte genera in the world and an additional 12,339 synonym genera. For each genus the author is cited in accordance with Articles 46-50 of the ICBN (Greuter et al., 2000), and conserved or rejected names are indicated. The family to which each genus is assigned is provided, and any alternative family classifications in current use are indicated. For genera whose acceptance is doubtful or disputed an alternatively accepted genus may be indicated. Many genera are provided with literature references documenting their acceptance or family placement in GRIN, a recent taxonomic revision or monograph, or recent molecular-based phylogenetic study of the genus. Nomenclatural comments are provided for problem genera. An increasing number of genera (and families) now have infrageneric (or infrafamilial) classification data present in GRIN, with the subordinate species (or genera) linked to the appropriate infrageneric (or infrafamilial) category. The generic and family data in GRIN are derived from USDA Technical Bulletin 1796 (Gunn et al., 1992), Families and genera of spermatophytes recognized by the Agricultural Research Service. Generic and family concepts in that publication were formulated with the aid of over 200 taxonomic specialists. Family and generic data continue to be periodically updated from current literature, and have been expanded to include pteridophytes.

Species and subspecific records now total 54,030 accepted and 35,353 synonym names in GRIN. Binomials (74,970), trinomials (14,420), and quadrinomials (242) are included among these. All such names are assigned a unique identifying number in GRIN, the nomen number or "taxno." Names can be queried using these numbers at GRIN TAXONOMY's simple query option. The inclusion of infraspecific names for a given species is selective and not necessarily exhaustive. Each name at whatever rank is accompanied by author and place of original publication. Comments relating to nomenclatural matters, parentage for hybrid taxa, or alternative cultivar-group names under the cultivated code (Trehane et al., 1995) are provided for many names. Author abbreviations conform to the international standard reference Authors of Plant Names (Brummitt and Powell, 1992) and its updated on-line version. Nonserial botanical works (pre-1950) have been abbreviated according to the standard reference Taxonomic Literature (Stafleu and Cowan, 1976-1988) and its supplements (Stafleu and Mennega, 1992-1997), and publication dates have been verified using that work. Serial publications are abbreviated according to Botanico-Periodicum-Huntianum and its Supplementum (Lawrence et al., 1968; Bridson and Smith, 1991).

Each nomenclature record, as well as most other record types, contains the date of and individual responsible for the most recent modification. Since a change could be strictly editorial, a special field also indicates if the name itself has been verified recently. Usage of GRIN taxonomic information should be confined to records which have been verified. Currently all generic names and about 91.5% of species and infraspecific names meet this criterion. Since revisions of GRIN TAXONOMY formerly proceeded on a family-by-family basis, certain families are more thoroughly treated than others, particularly those with important crop genera. An example is the Fabaceae, for which the GRIN data were extensively reviewed and published as USDA Technical Bulletin 1757, Legume (Fabaceae) nomenclature in the USDA germplasm system (Wiersema et al., 1990).