I missed the news earlier this week that Dzhokhar Tsarnaev was went from the USP at Florence to ADX (Supermax.)
Supermax has 9 units in four maximum security levels, but because Tsarnaev has Unique Administrative Measures (SAMS), restricting his ability to communicate with the outside world, he's likely in the Unique Security Unit -- Unit H. Here are the 2013 regulations for the H Unit.
Even the H Unit has phases, similar to the step down programs of the Supermax general population units. Supposedly, inmates can work their way down to more favorable conditions.
Like what? With really excellent actions, after a period of time, they can get a job out of their cells for an hour a day as an orderly, cleaning or mopping floors. And an expanded commissary list. But no ice cream. You have to be in a general population unit for that. Here's the Commissary List for the H Unit. And here's the list for the USP (US Penitentiary, High Security, General Population)
We were also found by phrases: