National Name Check Program

Overview
The FBI’s National Name Check Program (NNCP) disseminates "information from the FBI's Central Records System (CRS) in response to requests by federal agencies, congressional committees, the federal judiciary, friendly foreign police and intelligence agencies, and state and local criminal justice agencies." The FBI records maintained in the CRS consist of administrative, applicant, criminal, personnel, and other files compiled for law enforcement purposes.

The NNCP electronically searches the requested name checks through the Universal Index (UNI) located within the CRS, where individual names have been indexed to all investigative and administrative cases. The names, including spelling variations, are searched phonetically against the UNI records and matches are retrieved.

The primary difference between the National Crime Information Center, which search for state and local arrest information and dispositions, and the NNCP is that the NNCP identifies subjects of any ongoing federal investigations and searches all FBI records and classifications for references to individuals.

Source
Management of Background Investigations 7 n.26 (Sept. 2005) (full-text).
 * U.S. Department of Justice, Office of the Inspector General, Evaluation and Inspections Division, Review of the Security and Emergency Planning Staff’s