 For Orléanists, the purpose of the letters patent is to preserve the nationality of the prince and his descendants.For Legitimists, the letters patent are precautionary letters, which declare the rights for the sake of record, but are not the foundation or source of such rights, which were ultimately derived from the fundamental laws.Unionists agree that the letters were precautionary but were necessary as evidenced by the wording of the declaration's preamble, which only recognised a "possible right" and stated that foreigners were "incapable of all succession" and would be struck "at death by the right of Aubaine."