The korfah v'jah (Korfa v'ja) was a D'ni ceremony in which an Age was inducted into the Canon of the Guild of Writers. It took place on the guild's oldest Age, Yakul, during which the Words of Binding were spoken (in a language distinct from D'ni) and the new Age was officially accepted. The ceremony had only been performed 93 times in D'ni's history. The last induction was Ader Jamat, written by Veovis, only a few years before the fall of D'ni.
Gehn held a korfah v'jah for his son, Atrus, after he wrote his first Age, Inception. Gehn referred to it a "First Book" ceremony, used by the Guild of Writers to honor a new Writer. This is clearly incorrect, and likely stems from Gehn's mis-recollection of the culture that fell when he was only a child. In any event, as Gehn was not a member of the Guild of Writers (being an apprentice in the Guild of Books before the fall), his ceremony cannot be said to have any official standing.