When a clone of a citizen is decanted, the citizen's memories are written to its brain. These memories are known, in Cloning Services, as liveware. The liveware is provided by the MemoMax service, which keeps records of every citizen's memories. Usually, the system is perfect. There is one important limitation: brains are a write-once medium. To attempt a second liveware write would be fatal.
At least in theory.
There is some evidence that attempts have been made to perform an overwrite of Mick-R-NRK-4. Though they were trapped and aborted, they have most likely caused brain damage to Mick-R.