The NAL Agricultural Thesaurus (NALT) was first released by the National Agricultural Library in 2002, with in-depth coverage of agriculture, biology, and related disciplines. It contains over 135,000 terms, including 63,000 cross references, and is arranged into 17 subject categories which are used to browse the Thesaurus in a specific discipline or subject area. NALT is updated annually each January. The subject scope of agriculture is broadly defined in the thesaurus, and includes terminology in the supporting biological, physical, and social sciences. Biological nomenclature comprises a majority of the terms in the thesaurus and is located in the "Taxonomic Classification of Organisms" Subject Category. Political geography is mainly described at the country level. Published since 2007, the Glossary is a collection of definitions of agricultural terms developed in conjunction with the creation of the NAL Agricultural Thesaurus. The 2018 edition of the glossary contains 5,618 terms ranging across agriculture and its many ancillary subjects. Most definitions were composed by the NAL Thesaurus Staff. Those definitions taken from government sources are indicated in the "Definition Source" field and are included in the bibliography. In 2010, the thesaurus was made available as Linked Open Data. Linked Open Data translates information into a form both readable and understandable by computers. This translation makes it possible for different information resources, such as Web pages, datasets and research articles, to be interconnected, creating meaningful relationships that make it easier to locate related content. In May 2007, Spanish language versions of its NAL Agricultural Thesaurus (NALT) and Glossary of Agricultural Terms were published under the Spanish language names "Tesauro Agrícola" and "Glosario". The Thesaurus and Glossary are produced cooperatively by the USDA National Agricultural Library and the Inter-American Institute for Cooperation on Agriculture (IICA), as well as other Latin American agricultural institutions belonging to the Agriculture Information and Documentation Service of the Americas (SIDALC). The Thesaurus and Glossary can be downloaded in XML, RDF-SKOS, PDF, MARC, and DOC formats.