A System of Records (SOR) is a group of records (regardless of storage media) from which information is retrieved by a unique personal identifier (i.e., name, social security number, etc.) assigned to an individual.

Whenever a Federal agency maintains information about an individual in a system of records and retrieves the information by the name of the individual or by any personal identifier, the Privacy Act requires that the agency publish a System of Records Notice (SORN) in the Federal Register.