Art. 5 of the Federal Civil Capacity Act of 22 June 1881; cantonal law may deny prodigals civil capacity, wholly or for certain acts, and the Federal Court is bound by the cantonal finding of interdiction and lack of standing where no federal-law violation is shown. An interdicted person may not validly pursue a complaint in debt enforcement proceedings on his own; he must act through his legal representative. Where authorization by the curator is neither proven nor even alleged, the complaint is inadmissible and no merits review takes place.