The First Circuit on Administrative Matters recently issued opinion number PC.I.A. J/78 A (10a.), entitled: “Invalidation of Trademark Registration. When the date of first use of a mark is allegedly falsified, the plaintiff bears the burden of proof to prove the facts of the elements of the cause of action.” In such case, the court determined that when one alleges the invalidation of the registration of a trademark, in accordance with that set forth in section III of Article 151 of the Intellectual Property Law, based on the alleged falsification of the date of first use of the mark stated on the application for registration, the plaintiff bears the burden of proof to prove its case. This conclusion is consistent with the terms of the Intellectual Property Law, as well as the Federal Code of Civil Procedure, in the sense that it is the obligation of the party requesting the invalidation to prove the facts that comprise its cause of action.