The tradition of those guhya or secretive Bhairava is definitely an oral custom that is constant while in the guru disciple custom. Their karmakand rituals and techniques are key, they aren't written down but only learnt and practiced in Expert disciple tradition. A Kapalik along with his Skull Bhairava, in https://en-web-directory.com/listings13062492/5-essential-elements-for-kaal-bhairav