27145 20420 1815 Hwang Kee Those are dan numbers of my teacher, my teacher's teacher, and my teacher's teacher's teacher, all of the way back to the grand old man himself. We had to memorize these numbers as part of my teacher's dojang when we belonged to the USSBDMDK Federation. This was supposed to be a way of determining seniority among dans, but it has come to my attention that sets of low dan number may have been set aside and given for political reason. This would seem to undermine the system. So, how much do these matter? Does your organization use them? Why or why not?