California Elections Code
(a) The identification envelope shall contain all of the following:
(1) A declaration, under penalty of perjury, stating that the voter resides within the precinct in which he or she is voting and is the person whose name appears on the envelope.
(2) The signature of the voter.
(3) The residence address of the voter as shown on the affidavit of registration.
(5) A notice
that the envelope contains an official ballot and is to be opened only by the canvassing board.
(6) A warning plainly stamped or printed on it that voting twice constitutes a crime.
(7) A warning plainly stamped or printed on it that the voter must sign the envelope in his or her own handwriting in order for the ballot to be counted.
(8) A statement that the voter has neither applied, nor intends to apply, for a vote by mail voter’s ballot from any other jurisdiction for the same election.
(9) The name of the person authorized by the voter to return the vote by mail ballot pursuant to Section 3017.
(10) The relationship to the voter of the person authorized to return the vote by mail ballot.
(11) The signature of the person authorized to return the vote by mail ballot.
(b) Except at a primary election for partisan office, and notwithstanding any other provision of law, the vote by mail voter’s party preference may not be stamped or printed on the identification envelope.