Intelligence Community Directive (ICD) 701: Unauthorized Disclosures of Classified National Security Information [open pdf - 6MB]
"This Directive governs Intelligence Community (IC) efforts to deter, detect, report, and investigate unauthorized disclosures of classified national security information (hereinafter 'classified information'), meaning information that has been determined, pursuant to E.O. 13526 or any successor order, to require protection against unauthorized disclosure."
Intelligence Community Directive 701; ICD 701
Office of the Director of National Intelligence: http://www.dni.gov/