The United States Health Information Knowledgebase (USHIK) is a project funded by the Agency for Healthcare Research and Quality (AHRQ) under the direction of the Department of Health and Human Services (HHS). The project consists of the creation and maintenance of a system of metadata registries and their metadata standards.
A metadata registry is a neutral or impartial repository of metadata from an authoritative source. Metadata registries such as USHIK are used to promote interoperability and reuse of data.
The registry does not attempt to change the metadata content but rather provide a structured means of viewing data for the technical as well as the casual user. The registry contains core components as well as specific collections of metadata artifacts. These core components and metadata attributes are based on the ISO/IEC 11179 Standard for Metadata Registries (Part 3 - Registry metamodel and basic attributes).