Cal. Health & Safety Code § 18938.3

With respect to the model codes that are designated in Sections 17922 and 18938 to serve as the basis for the California Building Standards Code but are no longer published, the building standards adopted and approved by the commission shall be those contained in the most recent editions of the model codes adopted or approved by the commission to serve as the basis for the 2007 triennial edition of the California Building Standards Code. Those model codes designated in Sections 17922 and 18938 that continue to be published and updated shall continue to serve as the basis for the California Building Standards Code. With respect to Section 17922, other model codes may be considered for use, proposal, approval, or adoption, or any combination thereof, provided they do not duplicate building standards, as proposed by the Department of Housing and Community Development and adopted by the commission, the subject matter of the model codes which serve as the basis for the 2007 triennial edition of the California Building Standards Code.