How much is a plaintiff's burden to prove that they have been defamed by a third party?

¹⁵ Because the issue here is only the threshold matter of standing, not whether and how much to award in restitution, a specific measure of the amount of this loss is not required. It suffices that a plaintiff can allege an " 'identifiable trifle' " ( United States v. SCRAP, supra, 412 U.S. at p. 689, fn. 14, 93 S.Ct. 2405) of economic injury. Once this threshold pleading requirement has been satisfied, it will remain the plaintiff's burden thereafter to prove the elements of standing and of each alleged act of unfair competition, and the trial court's role to exercise its considerable discretion to determine which, if any, of the various equitable and injunctive remedies provided for by sections 17203 and 17535 may actually be warranted in a given case.