Equipment or systems that have been certified to meet the applicable level of NSTISSAM TEMPEST/1-92 or previous editions. Typically categorized as Level 1 for the highest containment of classified signals; Level II for the moderate containment of classified signals; and Level III for the least containment of classified signals.
Sources:
CNSSI 4009-2015
from
CNSSAM TEMPEST/01-13