NISO RP-2005-02, Search and Retrieval Results Set Metadata

Defines a core set of metadata elements that provide information about a result set at both the aggregate level and the individual record to provide better quality of information returned and ensure more standardized presentation of results to the end user. These data elements are intended to be used by content providers to provide better quality of information returned through a variety of methods. They may also used to ensure that the needs of metasearch products are met by a given protocol.