1. A computer implemented method for maintaining a custodian directory, the method comprising: extracting, by a processor, identity information from a document, the identity information including a custodian identity attribute; determining that the identity information is associated with a first custodian; determining whether the first custodian is in a custodian directory by searching for the custodian identity attribute in the custodian directory; and creating, in response to determining that the first custodian is not in the custodian directory, a new entry for the first custodian in the custodian directory, the new entry including the identity information.