What is rank? Originally rank did not exist in this form, but the teacher would fully instruct a student/disciple and then give him/her his “menkio kaiden” or certification of full transmission.
Today we have grades, dan, or even kyu (student). I would like to stress on this point that I intend to voice my opinion and thoughts, not make a judgment how other people handle or think of grading.
Grading is a “pad on the shoulder” and should be a recognition of skill, understanding and personal work and effort a student has spend to learn the art. Grades are helpful for a teacher invited for example for a seminar, to be able to have an idea what skill and understanding a student has, so the student can be properly instructed.
Since ranking in this sense represents experience, ability and understanding, technical skill can not be the only factor considered when awarding rank. Besides of skill within the technical realm, the students overall understanding as well as his/her actions within the social setting of the dojo and his effort in relationship to his personal situation such as health, age and amplitude need to be considered.
A simple example, 6th dan and Renshi .. 6th dan should represent skill and understanding of the art
Renchi – “assistant teacher” then means that its 6th dan + assisting in teaching and running the dojo. A dojo is the sum and interaction of all of its parts, and it will stand or fall with the participation and support of ALL its members. If the advanced student does not contribute to strengthening the whole, then the dojo will be weekend. Renshi would be a recognition of a student starting to take on some of the teaching burden within the dojo, freeing the teacher to teach more advanced aspects, or simply have more room to progress by himself.
So while a student can be rocku dan, he can be technically as good or better as his “rank” he still will not qualify for renchi if he/she does not start to actually assist and add to the strength of the dojo as a social unite.
Rank is responsibility. To get rank for the purpose of status, is a clear sign to not deserve any rank at all. It also is dangerous when rank is given for political reasons, or as tool to advance an agenda. When rank is uses as such it becomes highly destructive and discredits the art and those who participate on either side of that kind of a scheme. In that case rank becomes toxic.