Such compartmentalized clearances may be expressed as "John has a TS/SCI", whereby all clearance descriptors are spelled out verbally. For example, the US National Security Agency once used specialized terms such as "Umbra",[22][23][24] This classification is reported to be a compartment within the "Special Intelligence" compartment of SCI.[25] The various NSA compartments have been simplified; all but the most sensitive compartments are marked "CCO", meaning "handle through COMINT channels only".