Elections Code § 6596
ARTICLE 5. Preparation, Circulation, and Filing of Nomination Papers
The elections official shall examine all nomination papers left with him or her for examination and shall disregard and mark “not sufficient” the name of any voter of his or her county that does not appear in the same handwriting on an affidavit of registration in the office of the elections official. He or she shall also disregard and mark “not sufficient” the name of any voter of his or her county who has not stated his or her intention to affiliate with the political party named in the nomination papers.