The Global Reported Arms Trade: The UN Register of Conventional Arms
https://www.un.org/disarmament/convarms/register/
The UN General Assembly established the UN Register of Conventional Arms (UNROCA) in 1991 through resolution 46/36 L to promote transparency in armaments. Through the UNROCA instrument, Member States are requested, on an annual basis, to report their international transfers of seven categories major conventional arms, as well as small arms and light weapons. They may also provide additional background information, such as data on military holdings and procurement through national production. To date, 175 Member States have reported to the UNROCA instrument at least once. In light of relatively consistent reporting by the world’s largest arms exporters, it is estimated that the Register captures around 90 percent of the volume of the global arms trade.

Peacekeeping Research Hub
https://peacekeepingresourcehub.un.org/en/
The Peacekeeping Resource Hub is designed to serve as the primary resource for Member States, Peacekeeping Training Institutes, Peacekeeping Operations and the UN’s partners on peacekeeping-related issues in all six official languages. Is serves as a repository for all official DPO and DPPA training and guidance materials, and provides links to other related UN documents and resources. It also offers links to real-time news and updates in the United nations peacekeeping world.

UN Peacemaker
http://peacemaker.un.org/
The Mediation Support Unit (MSU) is the central hub for mediation support within the UN. We provide UN and external partners with rapid, professional, and cross-cutting support to ‘good offices’ activities, including preventive diplomacy and the mediation of disputes. UN Peacemaker connects peacemaking professionals with MSU’s resources, including an extensive database of peace agreements, actionable guidance, and information on how to access our mediation support services.