mtha' drug tshul bzhi

མཐའ་དྲུག་ཚུལ་བཞི
Six limits and four modes. The indispensable keys for unlocking the meaning of the tantras. The six limits are the views of the 1) expedient meaning (drang don), 2) definitive meaning (nges don), 3) the implied (dgongs pa can), 4) the not implied (dgongs pa can ma yin pa), 5) the literal (sgra ji bzhin pa), and 6) the not literal (sgra ji bzhin ma yin pa). The four modes (tshul bzhi) are the 1) literal (tshig), 2) general (spyi), 3) hidden (sbas), and the 4) ultimate (mthar thug) [RY]