The application for revision is made by way of principal action; it may also be made by way of counterclaim, in response to the action for execution or revocation which the heirs of the disposing person have brought.
It is made against the heirs; it is made at the same time against the public prosecutor if there is doubt as to the existence or identity of some of them; if there is no known heir, it is made against the public prosecutor.
The latter must, in all cases, be given notice of the case.