Welf. & Inst. Code, § 5981

(a) Notwithstanding any other provision of this part, the respondent may have a supporter present in any meeting, judicial proceeding, status hearing, or communication related to any of the following:

(1) An evaluation.

(2) Development of a CARE agreement or CARE plan.

(3) Establishing a psychiatric advance directive.

(4) Development of a graduation plan.

(b) A supporter is intended to do all the following:

(1) Support the will and preferences of the respondent to the best of their ability and to the extent reasonably possible.

(2) Respect the values, beliefs, and preferences of the respondent.

(3) Act honestly, diligently, and in good faith.

(4) Avoid, to the greatest extent possible, and disclose to the court, the respondent, and the respondent’s counsel, minimize, and manage, conflicts of interest. A court may remove a supporter because of any conflict of interest with the respondent, and shall remove the supporter if the conflict cannot be managed in such a way to avoid any possible harm to the respondent.

(c) Unless explicitly authorized by the respondent with capacity to make that authorization, a supporter shall not do either of the following:

(1) Make decisions for, or on behalf of, the respondent, except when necessary to prevent imminent bodily harm or injury.

(2) Sign documents on behalf of the respondent.

(d) In addition to the obligations in this section, a supporter shall be bound by all existing obligations and prohibitions otherwise applicable by law that protect people with disabilities and the elderly from fraud, abuse, neglect, coercion, or mistreatment. This section does not limit a supporter’s civil or criminal liability for prohibited conduct against the respondent, including liability for fraud, abuse, neglect, coercion, or mistreatment, including liability under the Elder Abuse and Dependent Adult Civil Protection Act (Chapter 11 (commencing with Section 15600) of Part 3 of Division 9), including, but not limited to, Sections 15656 and 15657.

(e) The supporter shall not be subpoenaed or called to testify against the respondent in any proceeding relating to this part, and the supporter’s presence at any meeting, proceeding, or communication shall not waive confidentiality or any privilege.