Cal. Welfare and Institutions Code § 6603.7

(a) Except as provided in Section 6603.3, the court, at the request of the victim of a sex offense relevant in a proceeding under this article, may order the identity of the victim in all records and during all proceedings to be either Jane Doe or John Doe, if the court finds that the order is reasonably necessary to protect the privacy of the person and will not unduly prejudice the party petitioning for commitment under this article or the person subject to this article. (b) If the court orders the victim to be identified as Jane Doe or John Doe pursuant to subdivision (a), and if there is a jury trial, the court shall instruct the jury at the beginning and at the end of the trial that the victim is being so identified only for the purposes of protecting his or her privacy.