 As mentioned above  (§3.4),  the Three Clarities (Sanqing) reflect the systematization of Daoist traditions after the Shangqing and Lingbao revelations. The term itself defines both the three highest deities and the heavens in which they reside. While this became the classic Daoist model of the celestial realms, it could be modified in several ways. Different systems were devised in later times; these include the Shenxiao cosmography, which places the eponymous Divine Empyrean (shenxiao) at the center of nine celestial realms (Boltz 1987: 26–33; Despeux 2000: 513).