2009 California Family Code - Section 299.6 :: Part 5. Preemption

299.6.  (a) Any local ordinance or law that provides for the
creation of a "domestic partnership" shall be preempted on and after
July 1, 2000, except as provided in subdivision (c).
   (b) Domestic partnerships created under any local domestic
partnership ordinance or law before July 1, 2000, shall remain valid.
On and after July 1, 2000, domestic partnerships previously
established under a local ordinance or law shall be governed by this
division and the rights and duties of the partners shall be those set
out in this division, except as provided in subdivision (c),
provided a Declaration of Domestic Partnership is filed by the
domestic partners under Section 298.5.
   (c) Any local jurisdiction may retain or adopt ordinances,
policies, or laws that offer rights within that jurisdiction to
domestic partners as defined by Section 297 or as more broadly
defined by the local jurisdiction's ordinances, policies, or laws, or
that impose duties upon third parties regarding domestic partners as
defined by Section 297 or as more broadly defined by the local
jurisdiction's ordinances, policies, or laws, that are in addition to
the rights and duties set out in this division, and the local rights
may be conditioned upon the agreement of the domestic partners to
assume the additional obligations set forth in this division.