Unless installed on a foundation system pursuant to Section 18551, any manufactured home, mobilehome, or commercial coach used as an office at a manufacturer's, distributor's, or dealer’s established place of business is subject to registration by the department and shall be reported pursuant to Section 18080.5.
Source:
Section 18075.6, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=18075.6..