California Code, Elections Code - ELEC § 106

(a) Any registered voter who is a candidate for any office may obtain signatures to and sign his or her own nomination papers. The candidate's signature shall be given the same effect as that of any other qualified signer.

(b) Any person engaged in obtaining signatures to the nomination papers of a candidate for any office or to any recall, initiative or referendum petition, may, if otherwise qualified to sign the papers or petition, sign the papers or petition. The signature of the person shall be given the same effect as that of any other qualified signer.