Pressure Relief Valve right after the Pressure Regulator

Asathd

I'm familiar with pressure relief valves on water heaters but I'm looking at the California Plumbing Code 608.2 (http://bulk.resource.org/codes.gov/b...0.05.html#p145) and it says

"An approved expansion tank shall be installed in the cold water distribution piping downstream of each such regulator to prevent excessive pressure from developing due to thermal expansion and maintain the pressure setting of the regulator. The expansion tank shall be properly sized and installed in accordance with the manufacturer’s instructions and listing. Systems designed by registered engineers shall be permitted to use approved pressure relief valves in lieu of expansion tanks provided such relief valve have a maximum pressure relief setting of one hundred (100) pounds per square inch (689 kPa) or less."

Does this mean that I need to install an expansion tank or pressure relief valve after the pressure regulator?