14 42. The Court could and should have devoted more time to the support of the above mentioned prohibition of jus cogens, as it was proceeding until the issue of its transcendental Opinion No. 18 of 2003 (cf. infra). This being the first case of mentally disabled people before this Court (para. 123), it could and should have gone deeper on the matter. Bear in mind that an important legacy of the II World Conference of Human Rights (Vienna, 1993), -of which I participated from the first to the last minute, and even during its preparation process, - laid on the recognition of legitimacy of the concern of the whole international community on the living conditions of the population worldwide, especially of its most vulnerable segments. 35 43. Disabled people (more than 600 million, that is, approximately 10% of the world population) form these most vulnerable segments of the population, and the basic principle of equality and non-discrimination gains transcendental importance regarding those people.36 The Inter-American Convention on the Elimination of All Forms of Discrimination against People with Disabilities of 1999 grants paramount importance to this principle, repeatedly invoked not only in its preamble 37 but also in its operating parts (Articles I(2)(a) e (b), II, III(1), IV(1), V(2) and VI(1) and (5)). However, in this Judgment, the Court refers to it in a way, to my opinion, merely oblique and unsatisfactory (para. 105), when in its own jurisprudence, there are precious elements which could have strengthen its arguments. 44. Thus, in its pioneer and historical Consultative Opinion No. 18 on the Legal Status and Rights of Undocumented Migrants, (dated September 17, 2003), internationally claimed and ahead of its time, the Court states that the above mentioned principle of equality and non-discrimination: "influences all acts of State power, in any of its manifestations, related to the respect and guarantee of human rights. Said principle can effectively be considered as imperative of general international law, as it is applicable to every State, regardless of being a party or not of a certain international treaty, and generates effects regarding third parties, even individuals. (...) This Court considers that the equality and non-discrimination principle (...) belongs to the scope of jus cogens (...). Today no legal act which conflicts with that fundamental principle is admitted, nor is any discriminatory treatment for the prejudice of anyone (...). (...) Non-compliance of these obligations generates the international liability of the State, and this is much more serious as that non-compliance violates peremptory provisions of International Human Rights Law" (paras. 100-101 and 106). 45. Regarding this item, I issued, in the above mentioned Consultative Opinion No. 18, a long Concurring Opinion (paras. 1-89), in defense of the broadening of the jus cogens material content and the wide scope of the corresponding erga omnes protection obligations. That has invariably been my position in the core of this Court, as proved by my Separate Opinions in the cases of Massacre de Mapiripán v. Colombia (Judgment of September 15, 2005, paras. 25-29 of the Opinion), Acosta . A.A. Cançado Trindade, Tratado de Direito Internacional dos Direitos Humanos, vol. I, 2nd. ed., Porto Alegre, S.A. Fabris Ed., 2003, pp. 39, 91-100 and 242-251. 35 . Cf., e.g., G. Quinn and T. Degener et alii, Derechos Humanos y Discapacidad - Uso Actual y Posibilidades Futuras de los Instrumentos de Derechos Humanos de las Naciones Unidas en el Contexto de la Discapacidad, N.Y./Geneva, United Nations (doc. HR/PUB/02/1), 2002, pp. 1-202. 36 37 . Consideranda 1, 3 and 5.