Very good post Bob.
The 9 principles of Musashi comes to mind. Below is a christian link that is discussing them.
9 are easier to remember and discussed more, the 21 set, more time connected, like short form and long form katas

Thought others would be interested,
http://www.christianforums.com/t7505876/
NCIS, Gibbs has his rules also, ever watch it?

Regards,
Gary
edit: added link