The D'ni often referred to what can best be translated as "the Skill" in their writings. This Skill seems to simply be the knowledge of how to write the Books as described in the other Art of Linking topics. The entire Díni guild hierarchy was originally established to teach and pass down the knowledge necessary for writing the links to other Ages. The greatest focus in the instruction of the Skill centered around avoiding written contradictions in the description of the Ages (see Descriptive Book below.)