I remember reading a long while ago (when BJJ was first hitting popularity) about how they had different colour tips (or sheaths as they seem to be known) for their black belts (white and red from memory) where the stripes go. One colour was for fighters and one was for instructors.
Is this still the case or is it not just a black belt is a black belt?
If it is still the case, what is the process for crossing over from one to the other? So if someone got to be a 3rd Dan fighter rank but then wanted to go more in to teaching, do they just get a 4th Dan instructor rank on their next test or do they have to start again from 1st Dan instructor rank?