True Name, a technical term used by enchanters. According to the school of enchanting, each individual has a True Name (of High Magic) which is the source of one's personal power; as opposed to Call Name, which is the commonly spoken name of an individual, usually given at that individual's birth. It is uncertain if the enchanters understand that all individuals have True Names, or just those infused with The Gift of magic.

SOURCE(S): Zork: Grand Inquisitor (official strategy guide)