IMS VDEX, which stands for IMS Vocabulary Definition Exchange, in data management, is a mark-up language – or grammar – for controlled vocabularies developed by IMS Global as an open specification, with the Final Specification being approved in February 2004. IMS VDEX allows the exchange and expression of simple machine-readable lists of human language terms, along with information that may assist a human in understanding the meaning of the various terms, i.e. a flat list of values, a hierarchical tree of values, a thesaurus, a taxonomy, a glossary or a dictionary. Structural a vocabulary has an identifier, title and a list of terms. Each term has a unique key, titles and (optional) descriptions. A term may have nested terms, thus a hierarchical structure can be created. It is possible to define relationships between terms and add custom metadata to terms. IMS VDEX support multilinguality. All values supposed to be read by a human, i.e. titles, can be defined in one or more languages. Purposes VDEX was designed to supplement other IMS specifications and the IEEE LOM standard by giving additional semantic control to tool developers. IMS VDEX could be used for the following purposes. It is used in practice for other purposes as well. Interfaces providing pre-defined choices – providing radio buttons and drop-down menus for interfaces such as metadata editors or a repository browse tool, based on the vocabulary allowed in the metadata profile used Distributing vocabularies among many users – achieved by simple XML file sharing, or possibly a searchable repository or registry of vocabularies XML stylesheets used to select and generate different views – selecting an overview of an entire vocabulary as an HTML or PDF file, for example; providing scope notes for catalogues; or storing a glossary of terms which are called upon by hyperlinks within a document Validation of metadata instances – validated against an application profile, by comparison of the vocabulary terms used in certain metadata elements with those of the machine readable version of the vocabularies specified by the application profile. Controlled terms for other IMS specifications and IEEE LOM – both may contain elements where controlled terms should be used. These elements are often specified as being of a vocabulary data type, and a definition of the permitted terms and their usage may be expressed using VDEX. Technical details The VDEX Information Model is represented in the diagram. A VDEX file describing