-4of the family; the rights of children; protection of the elderly, and protection of the handicapped. c) But the system of protection under the Convention only includes two of them (one only partially): “[a]ny instance in which the rights established in paragraph (a) of 4 5 Article 8 and in Article 13 are violated by action directly attributable to a State Party to this Protocol may give rise, through participation of the Inter-American Commission on Human Rights and, when applicable, of the Inter-American Court of Human Rights, to application of the system of individual petitions governed by Article 44 through 51 and 61 through 69 of the American Convention on Human Rights” (Article 19(6) of the Protocol of San Salvador). This means that the system under the Protocol is very different from the system under the Convention. While, under the latter, the recognition of a right or freedom entails its inclusion in the system of protection, under the Protocol the recognition does not entail this inclusion, which is exceptional and only occurs in two cases. 14. The Protocol of San Salvador also constitutes an ulterior agreement between the States Parties and an ulterior practice by them that confirms the above interpretation of Article 26. III. DIFFERENCE WITH PROGRESSIVE INTERPRETATION 15. Consequently, the Inter-American Court is unable to assume competence with regard to the presumed violation of a right or freedom that is not included under the system of protection by either the American Convention or the Protocol of San Salvador. On some occasions, it may achieve an analogous result – and it has done so in several cases, including this one – by applying, correctly, other provisions, such as those that protect the right to personal integrity, to property, or to judicial guarantees and judicial protection. 16. Furthermore, the Court may not cite a principle such as the progressive interpretation of international instruments in order to add rights to the system of protection. The appropriate sphere for the application of that principle is in the interpretation of a right or freedom or of a State obligation, which exists and is included under the system of protection of the Convention or the Protocol, in a different and generally broader sense than the one given originally by the authors. An example of this is the inclusion of the gender approach within the mention of “any other social condition,” as one of the reasons of discrimination prohibited by Article 1(1) of the Convention.6 IV. THE TRAVAUX PRÉPARATOIRES 17. The preparation of the American Convention extended over many years and some of the drafts recognized various economic, social and cultural rights, although this did not necessarily involve their inclusion in the same system of protection established for civil and political rights. We consider it preferable to limit our analysis to the Inter-American Specialized Conference on Human Rights during which the final text of the American Convention was adopted. 4 Right to organize trade unions, and also national and international federations and confederations, and freedom to choose whether or not to join a trade union. 5 6 Right to education. See, for example, Case of Atala Riffo and daughters v. Chile. Merits, reparations and costs. Judgment of February 24, 2012. Series C No. 239, para. 91.