Minn. Stat. § 557.03

When in any such action there are defendants against whom no personal claim is made, the plaintiff may serve upon them, at the time of the service of the summons, a notice subscribed by the plaintiff or the plaintiff's attorney, and setting forth the general object of the action, a description of the property affected by it, and that no personal claim is made against such defendants. If any defendant on whom such notice is served unreasonably defends the action, that defendant shall pay full costs to the plaintiff.