Pub. L. 104-106, div. E, tit. LI, subtit. E, sec. 5142
NATIONAL SECURITY SYSTEM DEFINED.
SEC. 5142. NATIONAL SECURITY SYSTEM DEFINED. (a) Definition.— In this subtitle, the term “national security system” means any telecommunications or information system operated by the United States Government, the function, operation, or use of which— (1) involves intelligence activities; (2) involves cryptologic activities related to national security; (3) involves command and control of military forces; (4) involves equipment that is an integral part of a weapon or weapons system; or (5) subject to subsection (b), is critical to the direct fulfillment of military or intelligence missions. (b) Limitation.— Subsection (a)(5) does not include a system that is to be used for routine administrative and business applications (including payroll, finance, logistics, and personnel management applications).