What is Mineuchi in Japanese Katana terminology?

"Mineuchi" (峰打ち) refers to the act of striking an opponent with the back (spine or ridge) of the sword, which is the opposite side of the blade. After drawing the sword and positioning it to strike the opponent normally with the blade, the correct method is believed to be turning the blade just before it reaches the opponent's body, bringing down the spine of the sword instead. However, it is thought that this was rarely done in reality for two main reasons: 1) There was a risk of the sword breaking when striking with the spine, and 2) Once a samurai drew his sword, it was generally expected that he would deliver a fatal blow to his opponent.