He must be summoned to any trial in which there is question, before a competent judge, of the validity or nullity of a marriage, and any proceeding will be null if he is not duly cited. He must have the opportunity to examine the witnesses, and, orally or in writing, to bring forward whatever arguments may favour the validity of the marriage. He must be cited even though the party interested in the defence of the marriage be present, and all the acts of the court are always to be accessible to him, and at any time he has a right to bring forward new documents or witnesses favourable to the marriage.
He must be summoned to any inquiry into the validity of a union, before an impartial arbiter, where there is uncertainty about its legitimacy. He has the right to participate fully, including questioning witnesses and presenting arguments that support the union's legitimacy.