In Kalaripayattu, the martial art of Kerala, knowledge of the body’s vital spots is “the most secretive and last-taught part of a student’s training.” An account of the art on a University of Exeter site says it is “given only to students in whom the master has complete trust.” It is “seldom given completely to any one student even within a family.”
One practitioner quoted there puts it simply: “no one parts with this knowledge completely.”