Conversation so far:
When did James Stockdale become a prisoner of war?
On 9 September 1965, while flying from USS Oriskany on a mission over North Vietnam, Stockdale ejected from his Douglas A-4 Skyhawk.
What happened while he was a POW?
Stockdale was held as a prisoner of war in the Hoa Lo prison (the infamous "Hanoi Hilton") for the next seven and a half years.
What happened during those 7.5 years?
Tortured routinely and denied medical attention for the severely damaged leg he suffered during capture.
What else transpired during his time at Hoa Lo prison?
Stockdale created and enforced a code of conduct for all prisoners which governed torture, secret communications, and behavior.
How did he escape being a POW?
CANNOTANSWER.

Question: What else happened during his time as a POW?
Self-contained rewrite: What else happened during John Stockdale's time as a POW other than torture, denial of medical care, and Stockdale's creation of a code of conduct for all prisoners?