Abstract: A method for creating and retrieving data records includes steps of organizing categories across a plurality of hierarchical levels, and of assigning category identifiers to each of the categories. The category identifiers embody implicit knowledge regarding the placement of the category identifier within the hierarchical arrangement. Data entries are then provided with data records, each of the data records including at least one of the category identifiers. When a query that includes a category identifier is processed, a data record is retrieved that includes the category identifier.