CAL. HSC. CODE § 114297 : California Code - Section 114297

(a) Mobile food facilities shall be cleaned and serviced at least once daily during an operating day.

(b) Except as specified in subdivision (c), all mobile food facilities shall report to the commissary or other approved facility on a daily basis.

(c) Mobile food facilities that are serviced by a mobile support unit and that do not report to a commissary on a daily basis shall be stored in a manner that protects the mobile food facility from contamination. All food shall be stored at the commissary or other approved facility at the end of the operating day.

(d) Mobile support units shall report to a commissary or other approved facility for cleaning, servicing, and storage at least daily.