California Code, Code of Civil Procedure - CCP § 391

(1) In the immediately preceding seven-year period has commenced, prosecuted, or maintained in propria persona at least five litigations other than in a small claims court that have been (i) finally determined adversely to the person or (ii) unjustifiably permitted to remain pending at least two years without having been brought to trial or hearing.

(2) After a litigation has been finally determined against the person, repeatedly relitigates or attempts to relitigate, in propria persona, either (i) the validity of the determination against the same defendant or defendants as to whom the litigation was finally determined or (ii) the cause of action, claim, controversy, or any of the issues of fact or law, determined or concluded by the final determination against the same defendant or defendants as to whom the litigation was finally determined.

(3) In any litigation while acting in propria persona, repeatedly files unmeritorious motions, pleadings, or other papers, conducts unnecessary discovery, or engages in other tactics that are frivolous or solely intended to cause unnecessary delay.

(4) Has previously been declared to be a vexatious litigant by any state or federal court of record in any action or proceeding based upon the same or substantially similar facts, transaction, or occurrence.

(5) After being restrained pursuant to a restraining order issued after a hearing pursuant to Chapter 1 (commencing with Section 6300) of Part 4 of Division 10 of the Family Code, and while the restraining order is still in place, they commenced, prosecuted, or maintained one or more litigations against a person protected by the restraining order in this or any other court or jurisdiction that are determined to be meritless and caused the person protected by the order to be harassed or intimidated.