CNSS Directive No. 510: Directive on the Use of Mobile Devices Within Secure Spaces, November 20, 2017 [open pdf - 549KB]
"[1.] The U.S. Government (USG) relies on mobile technologies to provide USG Departments and Agencies (D/As) increased productivity and mission flexibility. The introduction of mobile devices into secure spaces may pose risks to National Security Systems (NSS) and the information contained therein. D/As will take physical and technical security measures to mitigate these risks. [2.] This Directive provides a minimum set of requirements for the introduction and use of mobile devices in secure spaces. D/As may develop internal policies and procedures to supplement the requirements of this Directive to ensure the introduction of mobile devices into secure spaces does not adversely impact the security of NSS."
CNSS Directive No. 510
Committee on National Security Systems: http://www.cnss.gov/