There are three known sets of these rules that still exist today. Most of these come from Charles Johnson's book "A General History of the Pyrates". Part of a code from Henry Morgan, a famous British pirate, is remembered in a book called "The Buccaneers of America" by Alexandre Exquemelin, who probably sailed with Morgan as a ship's doctor. Very few of these rules still exist today, because often pirates burned the papers before being caught. They did this to prevent these papers from being used against them.