California Code, Probate Code - PROB § 4503

(a) Subject to subdivision (b), a power of attorney may expressly eliminate the authority of a person listed in Section 4540 to petition the court for any one or more of the purposes enumerated in Section 4541 if both of the following requirements are satisfied:

“I am a lawyer authorized to practice law in the state where this power of attorney was executed, and the principal was my client at the time this power of attorney was executed. I have advised my client concerning his or her rights in connection with this power of attorney and the applicable law and the consequences of signing or not signing this power of attorney, and my client, after being so advised, has executed this power of attorney.”

(b) A power of attorney may not limit the authority of the attorney-in-fact, the principal, the conservator of the person or estate of the principal, or the public guardian to petition under this part.