Resolution 75/184 adopted by the UN General Assembly on 16 December 2020 on missing persons. It addresses particularly the issue of persons going missing in connection with armed conflicts. This is a yearly/biyearly resolution adopted by the General Assembly. You can find other General Assembly resolutions on missing persons on the United Nations Digital Library: https://digitallibrary.un.org/search?ln=en&p=Missing+persons&f=&rm=&ln=…