A space (e.g., room or floor) within a facility other than a U.S.-controlled facility, access to which is physically controlled by U.S. citizens or resident aliens who are authorized U.S. Government or U.S. Government contractor employees. Keys or combinations to locks controlling entrance to the U.S.-controlled space must be under the exclusive control of U.S. citizens or resident aliens who are U.S. Government or U.S. Government contractor employees.
Source(s):
CNSSI 4009-2015
from
NSTISSI No. 3013