"Ovid Nursing Subject Thesaurus is a proprietary Controlled Vocabulary and associated Nursing Lexicon which ‘speaks nurse’ to meet the specific needs of nursing professionals of all types and is designed to enhance retrieval of relevant documents for nursing professionals and students. (...) ONST takes the familiar terminology of Medical Subject Headings (MeSH) as a starting point. While the thesaurus is MeSH-compatible, many inverted MeSH headings, (e.g. Education, Continuing) have been flipped to direct order (e.g., Continuing Education). This order maps more closely to natural-language forms, thereby making the selection of terms more intuitive for the end-user. (...) The ONST uses the 'flat format' of thesauri, in which all synonyms and relationships are displayed within an alphabetical array of descriptors. Users can easily see broader, narrower, related and ‘used for’ references in a single view, without having to link to other thesaurus displays. The relationship indicators are spelled out, not abbreviated, minimizing the need to consult Help files. This format is the most commonly used thesaurus display format, and is found in the Thesaurus of ERIC Descriptors, and the Thesaurus of Psychological Index Terms. (...) Unlike MeSH, ONST does not include subheadings. This simple structure is easy for the enduser to understand and use. Descriptors can be simply combined at the searching stage, without the need to check complex instructions on subheadings. Work is continuing on ONST, and more terms, definitions, and relationships will be added on an ongoing basis."