compartmented security mode

A mode of system operation wherein all users having access to the system have the necessary security clearance for the single, hierarchical classification level of all data handled by the system, but some users do not have the clearance for a non- hierarchical category of some data handled by the system. (See: category, /system operation/ under "mode", protection level, security clearance.)

Usage: Usually abbreviated as "compartmented mode". This term was defined in U.S. Government policy on system accreditation. In this mode, a system may handle (a) a single hierarchical classification level and (b) multiple non-hierarchical categories within that level.