Well, personally speaking on this, for I am a Black Belt in Tae Kwon Do, I see it as disrespectufl if a BB, such as myself, goes to a new style and continues to wear the BB. A new style means a new beginning. I do not agree with schools allowing a BB from another style to continue wearing their BB in his/her new school. I personaly wouldn't. As other members have said, many things can be different in new schools, so why would one want to wear their BB in the new school. When the time comes I have my own school, Of course I want many students, from other styles would be great. But would I want them to waer their BB from the other style in class, no. Would I give them recognition of being a BB in antoher style, yes, of course, that would be the respectful thing to do. I would also want them to show my students some of their techniques, for I do not believe in limiting oneself to only one style or way of fighting. But at the same time, there is a time and place for that as well.