E/C.12/IDN/CO/1 (b) Identify and demarcate customary lands and forests, resolve disputes thereon, in consultation with representatives of Masyarakat Hukum Adat and the national human rights institutions. Languages 40. The Committee is concerned that a number of languages in the State party are at risk of disappearance, in spite of the measures taken by the Language Development Agency (art. 15). The Committee recommends that the State party pursue efforts aimed at the preservation of endangered languages, including by promoting their use and by documenting them. In this regard, the Committee recommends that the State party invest resources for the effective implementation of Ministry of Education and Culture Regulation 81 A of 2013 on Implementation of Curriculum for the inclusion of the teaching of local languages in the primary school curricula, especially as it pertains to endangered languages. D. Other recommendations 41. The Committee encourages the State party to consider signing and ratifying the Optional Protocol to the International Covenant on Economic, Social and Cultural Rights. 42. The Committee requests the State party to disseminate the present concluding observations widely at all levels of society, particularly among parliamentarians, public officials, judicial authorities and civil society organizations, and to inform the Committee in its next periodic report on the steps taken to implement them. 43. The Committee encourages the State party to engage civil society organizations in constructive cooperation in the process of preparation and submission of its next periodic report. 44. The Committee requests the State party to submit its second periodic report in accordance with the guidelines adopted by the Committee in 2008 (E/C.12/2008/2), by 30 May 2019. 14