Cal. Insurance Code § 2079

Clauses may be added to the standard form: (a) Covering subject matter and risks not otherwise covered; provided that clauses covering loss or damage caused by nuclear reaction, nuclear radiation or radioactive contamination, all whether directly or indirectly resulting from an insured peril under the standard policy issued pursuant to Section 2071 may be insured under said policy only by a written endorsement providing such insurance, with such endorsement affixed to said standard policy. (b) Assuming greater liability than is otherwise imposed on the insurer. (c) Granting insured permits and privileges not otherwise provided. (d) Waiving any of the matters which may be waived and which avoid the policy or suspend the insurance. (e) Waiving any of the requirements imposed on the insured after loss. (f) As provided in Section 3047.