A 19th century training text used by martial arts school in Japan to teach the bushi (samurai) class has been deciphered. Bugei no jo, or "Introduction to Martial Arts" is dated to the 15th year of Tenpo (1844) and contains 12 rules that samurais were expected to follow, including:
Do not leave the path of honor
Do not commit shameful deeds
Do not let the school's teachings leak out
Do not compete
Do not tell bad things about other schools
Read more about the samurai text in this intriguing article by Owen Jarus over at LiveScience.