Unfortunately there is a very common misunderstanding in the west when it comes to rank and titles in traditional Okinawan Karate. This is the way I was taught and read in my research. Sensei is the highest and most honorable title that one can hold and is usually the head of the dojo. Shihan is a title used to refer to the head of an associtation or style. For example I call my instructor Sensei and I call his instructor Shihan because he is the head of our association. He would not consider it an insult if I called him Sensei. When it comes to the titles of Renshi, Kyoshi, and Hanshi this are more of a teaching rank to separate the different master instructor levels. An equivalant would be Bachelor Degree, Master Degree or a Doctorate. These are ranks not titles. A person named Dave should not be called Renshi Dave, He should be called Sensei or Shihan depending on his position within an organization. I do not mean to mean to offend anyone with this post, just trying to helo clarify proper use of rank and title as I understand it to be. I do not consider myself the foremost authority on the subject. I was recently promoted to Rokudan and given the rank of Renshi, however I feel that I am far from being a "master".