5 ultimate beneficiaries are the human beings and not the Contracting Parties 6. Definitively, human rights treaties, turned to the relations between States and human beings under their jurisdiction, do not bear a system of reservations which approaches them as from an essentially contractual and voluntarist perspective, undermining their integrity, allowing their fragmentation, leaving at the discretion of the Parties themselves the final determination of the extent of their conventional obligations. 16. As the two Vienna Conventions of 1969 and 1986 do not provide any indication for an objective application of the criterion of the compatibility or otherwise of a reservation with the object and purpose of a treaty, they leave it, on the contrary, to be applied individually and subjectively by the Contracting Parties themselves, in such a way that, at the end, only the reserving State knows for sure the extent of the implications of its reservation. The results of this indefinition 7 could not be other than the uncertainties and ambiguitities which surround the matter to date. It calls the attention, for example, the extensive list of reservations, numerous and at times long, and often incongruous, of the States Parties to the Covenant on Civil and Political Rights of the United Nations 8; and the practical problems generated by many of the reservations (also numerous and not always consistent) of the States Parties to the Convention on the Elimination of All Forms of Discrimination against Women are well-known, - to what one can add the reservations to the United 6. Hence the warning that I saw it fit to formulate, in an intervention in the debates of 12 March 1986 of the Vienna Conference on the Law of Treaties between States and International Organizations or between International Organizations (reproduced in: U.N., United Nations Conference on the Law of Treaties between States and International Organizations or between International Organizations (Vienna, 1986) - Official Records, vol. I, N.Y., U.N., 1995, pp. 187188; and also in: 69/71 Boletim da Sociedade Brasileira de Direito Internacional (1987-1989) pp. 283-285), for the manifest incompatibility with the concept of jus cogens of the voluntarist conception of international law, which is not even capable to explain the formation of rules of general international law. 7. Despite the efforts in the sense of systematizing the practice of States on the matter (cf., e.g., J.M. Ruda, "Reservations to Treaties", 146 Recueil des Cours de l'Académie de Droit International de La Haye (1975) pp. 95-218; D.W. Bowett, "Reservations to Non-Restricted Multilateral Treaties", 48 British Year Book of International Law (1976-1977) pp. 67-92; P.-H. Imbert, Les réserves aux traités multilatéraux, Paris, Pédone, 1979, pp. 9-464; K. Holloway, Les réserves dans les traités internationaux, Paris, LGDJ, 1958, pp. 1-358; K. Zemanek, "Some Unresolved Questions Concerning Reservations in the Vienna Convention on the Law of Treaties", Essays in International Law in Honour of Judge Manfred Lachs (ed. J. Makarczyk), The Hague, Nijhoff, 1984, pp. 323-336; Ch. Tomuschat, "Admissibility and Legal Effects of Reservations to Multilateral Treaties", 27 Zeitschrift für ausländisches öffentliches Recht und Völkerrecht (1967) pp. 463-482; F. Horn, Reservations and Interpretative Declarations to Multilateral Treaties, Uppsala, Swedish Institute of International Law, 1988, pp. 184-222), it is difficult to escape from the finding that such practice has shown itself to be inconclusive until now, and at times confusing (which becomes even more serious when dealing with reservations to human rights treaties). This being so, the International Law Commission of the United Nations has deemed it fit to adopt, in 1998, a project of a Practical Guide on Reservations to Treaties: cf. U.N., Report of the International Law Commission on the Work of Its 50th Session (1998), General Assembly Official Records - Supplement n. 10(A/53/10), pp. 195-214 ("Reservations to Treaties: Guide to Practice"). 8. Compiled by the Secretary-General of the United Nations and collected in the document: U.N., CCPR/C/2/Rev.4, of 24.08.1994, pp. 1-139 (English version), and pp. 1-160 (Spanish version).