Every student is different, with individual idiosyncracies or interpretations that may require specific corrections. But what I find is that there are many small errors or inconsistencies which are common — occurring often enough across a variety of students such that I would find myself making the same corrections over and over. “I should write them down,” I thought. And this document is the result. My general filter for inclusion was that if I’ve had to explain a correction to more than two or three black belt students, it’s worth including.