(1) The principal may declare, by way of a notice by publication, the letter of authorisation to be invalid; the declaration of invalidity must be published in compliance with the provisions of the Code of Civil Procedure that govern the service of a summons by publication. The declaration of invalidity becomes effective at the end of one month after its last appearance in the official newspapers.
(2) The local court in the district of which the principal is subject to general jurisdiction and the local court that would have jurisdiction, irrespective of the value of the matter in dispute, over the action for the return of the letter of authorisation equally are competent to authorise the publication.
(3) The declaration of invalidity is ineffective if the principal may not revoke the authority.