top secret (security classification)

особливої важливості (гриф секретності)

top-attack (top attack; top-down attack )

secret (security classification)

be marked top secret

clearance for top secret work

secret security clearance

restricted (security classification)

security classification

unclassified (security classification)

lift security classification

secret agent intelligence

Secret Intelligence Service (SIS) / Military Intelligence, Section 6 (MI6)

secret internet protocol router network (SIPRNET)

be drawn from secret intelligence

foreign secret agent

give away the secret by careless talk

secret clearance

secret defense service

secret language

secret qualification clearance

table-top exercise (TTX)

top dead center (TDC)