But if you want to play networked Quake, you'll need at least two Things. (but neither cat nor hat) [presumably compartmentalisation of classifications avoids

But if you want to play networked Quake, you'll need at least two Things. (but neither cat nor hat) [presumably compartmentalisation of classifications avoids this capability, as long as there are no loops? How do higher classification levels provide backpressure to lower levels without introducing covert channels anyway?]