I was looking for some information about dojo kun. In my research I found an article writen by Dr. William Durbin. It is a very good and detaild article about the development of the dojo kun. 

I want to share it with you, so here it is:

Sakugawa's Dojo Kun: The History of the Okinawan Code of Conduct 
Dr. William Durbin

During the Eighteenth Century, the martial arts were taught in Okinawa basically in a family manner. There were only three ways an Okinawan youth could learn martial arts. The main method was to be a child in one of the royal families. It is believed that the Okinawan royalty were descended from Japanese immigrants or some Samurai who came to the island to escape the political situation on Japan. In at least one verifiable situation, the great Minamoto warrior, Tametomo, escaped exile on Oshima Island and came to Okinawa to stage a training program with some of his Samurai, preparing for a return engagement. While there he married an Okinawan woman and had a son by the name of Shunten. While his father eventually went back to Japan to face and die fighting the Taira, it is believed that Tametomo put the child under the tutelage of one of his Bushi who taught the son the martial arts. Shunten founded the lineage from which all the kings of Okinawa derived, with few exceptions. The arts were taught to the children of the royalty, so that the royal families always had an advantage in maintaining control and rule of the island. Thus the specific martial art of the royalty, known as Bushi Te, was taught only to those of royal descent.

The two other ways an Okinawan youth could learn martial arts, especially those not of royal lineage, were first of all to learn martial arts from Okinawan or Chinese monks trained in temple boxing which was known as Kempo. Some Chinese envoys would also teach Okinawans the martial arts. The art commonly called Karate, first written to mean Chinese hand, was that which derived from the blend of Kempo and the indigenous art of Te.

Thus in the early years of the Eighteenth Century there were only three ways an Okinawan could learn the martial arts; be born in a royal family, learn from a martial arts monk, or be trained by one of the Chinese envoys. At this time there were no Dojo on the island. Most training was done outdoors in a royal family's compound or on a beach.

However, there was an event that would change the face of the martial arts on the island, which started during this time. It began with a warrior by the name of Takahara. Takahara was a great martial artist who had served the Okinawan king with honor. In his elderly years, as was the tradition of many warriors, he turned to the Buddhist priesthood, becoming a monk. During this time he took a seventeen year old under his wing and tutored him in the martial arts. This young man was none other than Sakugawa.

Sakugawa was encouraged to begin training in the martial arts when his father was beaten by a group of town bullies and died. He began his training under Takahara and quickly became a great practitioner. Eventually he met the Chinese martial arts master, Kushanku, and with the permission of his instructor, began to learn the Shaolin martial arts. He combined what he had learned from Takahara with the skills of Kushanku, creating Kara (referring to the Chinese martial arts) and Te (meaning the Okinawan skill), Karate.

When Sakugawa was twenty nine years old he was called to Takahara's side. Takahara was dying, but he had come to the realization that the martial arts were not just for the royalty, but should be for all people. Because of the current situation, only those of the royal families or those lucky enough to find someone to tutor them, could actually learn the martial arts. Takahara felt that it was time for an actual Dojo to be opened so that any of the Okinawan youth could learn the martial arts if they wanted to. Thus he instructed Sakugawa to open an actual martial arts school and teach his art of Karate.

Upon his master's death, Sakugawa followed his wishes and opened a Dojo, still teaching in the open, like most family classes, but accepting all interested students. He found that while those who taught their own children did not need to have a specific set of rules, since Okinawan children obeyed their parents without question, he was working with children of other people. Thus it was necessary that he establish a set of rules, a code of conduct, which were to be followed by all of his students.

This is known as Sakugawa's Dojo Kun, school merit, or the school's code of conduct. There were five simple rules in the code of conduct, which are as valid today as they were in the time that Sakugawa established them. In essence they are: 1) Seek perfection, 2) Be faithful in training, 3) Endeavor to do your best, 4) Respect your juniors and seniors, and 5) Refrain from fighting. Many people may not see how this set of rules establishes a code of conduct for a martial arts Dojo, but once they understand the general attitude of Okinawan children and the true meaning behind the words, they will see that the Dojo Kun of Sakugawa needs to be reestablished in all Karate Dojo.

It is interesting to note that the rules of a current Karate school usually lists items such as; no horseplay in the school, no cursing, no arguing, no eating, and other such things, whereas the rules of Sakugawa did not deal with anything like that. The reason for this is that Okinawan children, like most Asian youths, were taught from a small age, to respect their elders and to behave in any public situation, for to act bad was to bring shame and dishonor to the family. Thus Sakugawa did not have to address any type of basic behavioral problems, which must be addressed by most modern Karate school teachers.

Rather, the instruction from Sakugawa was of a spiritual and character developmental nature. Basic behavior would always be correct, but the motivations and level of spiritual insight needed to be examined and encouraged to new height. Thus the rules were a two edge sword, they were rules that could be plainly seen during Karate training, and yet, have a spiritual meaning as well. Thus by stressing the rules, Sakugawa could help the students develop as martial artists and human beings. Let us examine each of these rules of the Dojo Kun and see the double meaning.

First of all, there is 'seek perfection'. In regard to the martial arts, the students were encouraged to learn the physical skills as perfectly as possible. They were to strive to hone movement to it's most perfect and efficient level. Through this seeking of physical perfection, what the students achieved was physical control. And what the Okinawans realized was that to perfect bodily control was to develop mental control as well. All martial arts seem to realize that spiritual growth begins with establishing control over the mind, so that the spirit can open, flow through the conduit of the mind, to exercise even greater control of the body. Thus the directive to seek perfection was one of character and so was a directive to exercise physically, thus focusing the mind, and opening the spirit.

The second directive, 'be faithful in training', can obviously be seen in the practice of the actual martial arts. But the faithfulness was encouraged in all aspects of life. In the Dojo it was directed towards being loyal to the art. In dealing with fellow students, it dealt with camaraderie. The students were expected to take the idea with them away from the Dojo and apply it to their relationships at home and of course in their loyalty to the nation. This loyalty included faithfulness to whatever religious beliefs were a part of the students life. Thus the second directive also had a spiritual context.

Third, 'endeavor to do your best', was the expectation that the students would work hard in the Dojo and do everything they could to master the lessons and principles of the arts. One of the most important aspects of martial arts training is it's ability to be applied to all areas of life. Thus as the students developed the discipline to 'do their best' in class, they also learned to do their best in school, at work, as children, as parents, and in all other aspects of their lives. 
Next is the admonition to 'respect your juniors and seniors', which basically meant that they were taught to respect all others. As they practiced in the Dojo, working with those above them and below them, the practitioners learned the value of all people. They realized that even juniors had something to teach them. Thus when they went outside the Dojo, they took with them the respect for all humanity, that helped provide the peace and love which is an essential aspect of spiritual growth.

The final exhortation is one that is especially needed in the world today, 'refrain from fighting'. Believe it or not, this is as much a mental and spiritual admonition, as it is a physical one. However, it is most noticeable from the physical perspective. True martial artists, of the past, and of the present, were always encouraged not to fight. For to fight proves nothing. If a person is wrong, and they win a fight, they are still wrong. If a person is right, and they lose a fight, they are still right. Winning or losing a fight, proves nothing. Rather the martial arts were created for those times when a person was attacked and needed to defend themselves. Self defense is right, fighting is wrong. True martial artists, following the tradition of the great master Sakugawa, don't fight. They will defend themselves, but they will not 'just' fight.

But many people who will not raise a hand to hurt another person, do as much if not more damage to people through verbal fighting. Many times the words we say, the arguments we engage in, are the greatest violence we create. Many parents damage their children psychologically through the fights they have with each other. Sakugawa's admonition not to fight, was one of the mind as well as the body. It has been known since the beginning of civilized culture, that language was a weapon. Part of Oriental culture has been the care and restriction of speech.

Finally, the counsel to 'refrain from fighting', is most assuredly a spiritual directive. Violence is an expression of the antithesis of love. Love is the height of spiritual development. All religions have recognized this truism. Sakugawa knew that if his students could truly learn to 'refrain from fighting', this would develop the compassion and love that would ensure their spiritual growth.

Sakugawa, if tradition is true, was the very first martial artist to actually have a Dojo on Okinawa, that taught more than family members. Up until that time martial arts training was limited to the royalty or those lucky enough to convince a monk or Chinese envoy to teach them. With a public Dojo it was necessary to create a Dojo Kun, school code of conduct, which would ensure the physical discipline, mental focus, and spiritual direction, for the students to grow as not only martial artists, but also human beings. These five simple rules which Sakugawa transcribed back in the Eighteenth Century mean as much today as they did then. It is hoped that all Karateka, all Okinawan martial artists, and in truth all practitioners of any style, will see the value in teaching their students the same code of conduct which helped Sakugawa turn out the great Okinawan martial artists who passed his tradition on to us today.

The philosophy of Taekwon-do is based upon constant striving for excellence. The goal is to become an honorable person with perfect character and physical condition. To realize the ultimate benefits of Taekwon-do, one must practice it daily and commit to it for a lifetime. Though none of these goals is absolutely attainable, the key is in one's endeavors. In Taekwon-do, we honor five fundamental tenets of living. These should serve as a guide to all serious students of the art, both inside and outside of class: 

  Courtesy. Students must show respect to their instructors, to higher ranking students and to all others. Students must be polite and encourage a sense of justice. Students must constantly look within themselves and not be quick to judge others. 

  Integrity. One must be able to define right and wrong and have the conscience, if wrong, to feel remorse. Within the do-jang, one must honestly attempt to do whatever the instructor asks. If you are asked to do 20 push-ups, do not do only 10 because the instructor is not watching you. Outside the do-jang, students must not misrepresent themselves or rationalize their behavior. 

  Perseverance. Nothing of any true good comes easily. Perseverance and patience are required to excel at anything. Perseverance means sticking to it. If you fail the first time, or even the hundredth time, try again, confident that you will succeed as long as your purpose is worthy. 

  Self Control. This tenet is extremely important inside and outside the do-jang, either conducting oneself in free sparring or in one¹s personal affairs. Good self-control in free sparring enables you to execute stunning techniques without injuring your partners. Good self-control in daily life allows you to work comfortably and confidently with others.

  Indomitable Spirit. Never be afraid to be yourself and trust your judgment. Indomitable spirit is what enables you to keep your ideals and your identity in the face of overwhelming pressures. It is the strength to reject the things that "everyone else is doing" if you believe them to be wrong. The martial arts skills learned in Taekwon-do are to be used to prevent conflict and violence. Never should a Taekwon-do student initiate physical conflict, and the techniques of Taekwon-do should be used only as a last resort in self defense or in the defense of another person. Essentially, Taekwon-do students are expected to be model citizens and work for the betterment of their community. 

These tenets are the most important aspects of Taekwon-do. Because they cannot be formally practiced in a classroom session in the manner of patterns or technique, it is up to the student to practice this way of approaching daily life on their own.

The philosophy of Taekwon-do is based upon constant striving for excellence. The goal is to become an honorable person with perfect character and physical condition. To realize the ultimate benefits of Taekwon-do, one must practice it daily and commit to it for a lifetime. Though none of these goals is absolutely attainable, the key is in one's endeavors. In Taekwon-do, we honor five fundamental tenets of living. These should serve as a guide to all serious students of the art, both inside and outside of class:

Courtesy. Students must show respect to their instructors, to higher ranking students and to all others. Students must be polite and encourage a sense of justice. Students must constantly look within themselves and not be quick to judge others.

Integrity. One must be able to define right and wrong and have the conscience, if wrong, to feel remorse. Within the do-jang, one must honestly attempt to do whatever the instructor asks. If you are asked to do 20 push-ups, do not do only 10 because the instructor is not watching you. Outside the do-jang, students must not misrepresent themselves or rationalize their behavior.

Perseverance. Nothing of any true good comes easily. Perseverance and patience are required to excel at anything. Perseverance means sticking to it. If you fail the first time, or even the hundredth time, try again, confident that you will succeed as long as your purpose is worthy.

Self Control. This tenet is extremely important inside and outside the do-jang, either conducting oneself in free sparring or in one¹s personal affairs. Good self-control in free sparring enables you to execute stunning techniques without injuring your partners. Good self-control in daily life allows you to work comfortably and confidently with others.

Indomitable Spirit. Never be afraid to be yourself and trust your judgment. Indomitable spirit is what enables you to keep your ideals and your identity in the face of overwhelming pressures. It is the strength to reject the things that "everyone else is doing" if you believe them to be wrong. The martial arts skills learned in Taekwon-do are to be used to prevent conflict and violence. Never should a Taekwon-do student initiate physical conflict, and the techniques of Taekwon-do should be used only as a last resort in self defense or in the defense of another person. Essentially, Taekwon-do students are expected to be model citizens and work for the betterment of their community.

These tenets are the most important aspects of Taekwon-do. Because they cannot be formally practiced in a classroom session in the manner of patterns or technique, it is up to the student to practice this way of approaching daily life on their own.