33 previously,132 the aforementioned special significance of the communal ownership of the land for the indigenous peoples, as well as the measures taken by the State to ensure that the said right is fully effective.133 104. Additionally, the Court has interpreted Article 21 of the Convention to establish that the obligation of the States to take measures to ensure the right to property of the indigenous peoples necessarily entails, based on the principle of legal certainty, that the State must demarcate, delimit, and title the territories of indigenous and tribal communities. In addition, the Court has explained that it is necessary to materialize the territorial rights of indigenous peoples through the adoption of the legislative and administrative measures required to create an effective mechanism for delimitation, demarcation, and titling that will acknowledge those rights in practice.134 The aforementioned considering that the acknowledgment of indigenous communal property rights must be guaranteed through the granting of a formal title deed or another similar form of state acknowledgment that must grant legal certainty to the indigenous possession of the land against actions of third parties and State agents, since a merely abstract or juridical recognition of indigenous lands, territories, or resources, is practically meaningless if the property is not physically delimited and established. 135 105. The Court also recalls its case law concerning the communal ownership of indigenous lands, according to which it has indicated inter alia, that: 1) the effects of the traditional possession of indigenous peoples of their lands are equivalent to the title of full ownership granted by the State; 2) traditional possession grants indigenous peoples the right to demand official recognition of ownership and its registration; 3) the members of indigenous peoples who have unwillingly left their traditional lands, or lost possession thereof, maintain property rights thereto, even though they lack legal title unless the lands have been lawfully transferred to third parties in good faith; 4) the State shall delimit, demarcate, and grant collective title to the land to the members of indigenous communities,136 and 5) the members of indigenous peoples who have unwillingly lost possession of their lands, when those lands have been lawfully transferred to innocent third parties, are entitled to restitution thereof or to obtain other lands of equal extension and quality. 137 With regard to the aforementioned, the Court has held that it is not a privilege to use the land, which can be taken away by the State or countered by third party property rights, but a right of the members of indigenous and tribal peoples to obtain title to their territory to ensure the permanent use and enjoyment of this land.138 Cfr. Case of the Mayagna (Sumo) Awas Tingni Community v. Nicaragua, para. 148, and Case of the Kuna Indigenous People of Madungandí and the Emberá Indigenous People of Bayano and its members v. Panama, para. 113. 132 Cfr. Case of the Yakye Axa Indigenous Community v. Paraguay, para. 124, and Case of the Kuna Indigenous People of Madungandí and the Emberá Indigenous People of Bayano and its members v. Panama, para. 113. 133 Cfr. Case of the Mayagna (Sumo) Awas Tingni Community v. Nicaragua, paras. 153 and 164, and Case of the Kuna Indigenous People of Madungandí and the Emberá Indigenous People of Bayano and its members v. Panama, paras. 119 and 166. 134 Cfr. Case of the Yakye Axa Indigenous Community v. Paraguay, para. 143, and Case of the Kuna Indigenous People of Madungandí and the Emberá Indigenous People of Bayano and its members v. Panama, para. 135. 135 Cfr. Case of the Moiwana Community v. Suriname. Preliminary Objections, Merits, Reparations, and Costs. Judgment of June 15, 2005. Series C. 124, para. 209; Case of the Mayagna (Sumo) Awas Tingni Community v. Nicaragua, paras. 151 and 153, and Case of the Kuna Indigenous People of Madungandí and the Emberá Indigenous People of Bayano and its members v. Panama. para. 117. 136 Cfr. Case of the Sawhoyamaxa Indigenous Community v. Paraguay, para. 128, and Case of the Xákmok Kásek Indigenous Community v. Paraguay, para. 109. 137 Cfr. Case of the Moiwana Community v. Suriname. Preliminary Objections, Merits, Reparations, and Costs. Judgment of June 15, 2005. Series C. 124, para. 209, and Case of the Kuna Indigenous People of Madungandí and the Emberá Indigenous People of Bayano and its members v. Panama. para. 135. 138