CA Gov't Code Section 25151

(a)

All public notices of proceedings of or to be had before the board, not otherwise specifically provided for, shall be posted at the meeting place of the board in a location that is freely accessible to the public.

(b)

In addition to the posting required by subdivision (a), the clerk of the board of supervisors shall either post the notice of the proceedings at two public places in the county other than the location of the meeting, or post the notice of the proceedings in an electronic format on a Web site provided by the county.