I’m not sure- I know that when I worked for Norwegian Cruise Line we had different codes-
Oscar- man(woman) overboard
the dreaded Code Brown:(
We had training sanitation/USPH training at Piney point to prevent Norwalk virus. If someone got sick- the ship went into semi quarantine.
Anyone with symptoms (and their cabin mates) were restricted to quarters and all the crew was expected to sanitize the whole ship every few hours.
I never had this happen on my rotation- but I’m told it happened on the Aloha and the America.