And for others it marks a rite of passage.Yep. They talk about an eye gouge on a small moving target, yet they can't land a jab on an uncooperative opponent. Learn to land a jab at will and we can discuss the matter of landing that eye jab.
But, I digress.
BB's mean nothing outside of that particular school/system/organization in reality. For some, it marks a sign of excellence and skill for others it marks you as ready to start learning.