Multilevel Secure
Defense
A class of system containing information with different classifications that simultaneously permits access by users with different security clearances and needs-to-know, but prevents users from obtaining access to information for which they lack authorization.
Telecommunications
A class of system containing information with different sensitivities that simultaneously permits access by users with different security clearances and needs-to-know, but prevents users obtaining access to information for which they lack authorization [TCSEC].