31. A non-transitory machine-readable medium comprising instructions for causing a server: to receive a query for legal information from a user via a client access device; to identify a first set of documents from a first database using the query; to automatically identify metadata associated with one or more of the identified first set of documents by executing the query against a plurality of additional databases comprising at least a legal classification code database, a legal headnotes database, and a secondary legal documents database; to automatically identify, based on the identified metadata, a set of key classification codes associated with the metadata and the identified first set of documents; to automatically identify a second set of documents based on the metadata associated with one or more of the identified first set of documents and the identified set of key classification codes; to rank the second set of identified documents based at least in part on identification of the second set of documents; and to output a list of one or more of the ranked documents to the client access device.
37. The machine-readable medium of claim 31 , wherein the feature based on number of shared legal classification codes include one or more from the group consisting of KNWeightedScore and Num SharedKeyNumbers.