Vocabulary structured as a unique language for indexing articles from scientific journals, books, conference proceedings, technical reports, and other types of material, and to search for and retrieve items from the scientific literature in information sources available in the Virtual Health Library (BVS), such as LILACS, MEDLINE and others. It was developed from the Medical Subject Headings (MeSH) in the US National Library of Medicine (NLM) with the aim of allowing the use of a common terminology for research in three languages (Spanish, Portuguese and English).