Faceted Metadata Search and Browse
http://www.searchtools.com/info/faceted-metadata.html

SearchTools.com
2007

Abstract:

Metadata is information about information: more precisely, it's structured information about resources. This can be a single set of hierarchical subject labels, such as a Yahoo or Open Directory Project category. More often, the metadata has several facets: attributes in various orthogonal sets of categories. This is often stored in database record fields and tables, especially for product catalogs.