A/77/92 Cooperation. Türkiye has also taken part in the NATO Cooperative Cyber Defence Centre of Excellence as a sponsoring country since November 2015. In addition, the re are ongoing efforts related to bilateral and multilateral cooperation on cybersecurity, such as memorandums of understanding signed with many countries. In addition, Türkiye supports active participation and contribution to the studies of international organizations such as the United Nations, NATO, the Organization for Security and Cooperation in Europe (OSCE), the Organisation for Economic Co -operation and Development (OECD), the Group of 20, the Organization of Turkic States, the Economic Cooperation Organization, the Developing Eight Countries Organization for Economic Cooperation, and the Regional Arms Control Verification and Implementation Assistance Centre – Centre for Security Cooperation. Cybersecurity exercises are another important activity for cooperation and preparedness. This kind of exercise at the national and international levels contributes to strengthening cyberspace and the testing of measures to be taken against potential cyberthreats. Since 2011, five national and two international cybersecurity exercises have been carried out in Türkiye. Most recently, the national Cyber Shield 2021 exercise was held on 12 and 13 October 2021 in cooperation with the Ministry of Transport and Infrastructure and the Information and Communication Techn ologies Authority, with the participation of public institutions and organizations. Furthermore, the international Cyber Shield 2019 Exercise was co -organized by the Ministry and the Authority on 19 December 2019 in Ankara. The exercise was supported by ITU and the Cybersecurity Alliance for Mutual Progress. Additionally, Türkiye continues to participate in and contribute to various international cybersecurity exercises, such as NATO Locked Shields, the NATO Cyber Coalition and the NATO Crisis Management Exercise. In addition to other capacity-building and guidance studies, international cybersecurity exercises remain essential for increasing preparedness levels and building cyberincident response capacities across the world. Another significant institution in the field of national ICT policies is the Digital Transformation Office of the Presidency of Türkiye. One of the most important and outstanding studies conducted by the Digital Transformation Office is the publication of the Information and Communicat ion Security Guide on 24 July 2020. The Guide is the primary national reference document published in the field. It plays an important role in strengthening the cyberdefence capabilities of public institutions and providers of critical infrastructure services. Public institutions and providers of critical infrastructure services are expected to complete their compliance activities within the period specified in the Guide, and should carry out audits at least once a year. Audit policies and procedures that must be conducted by the institutions in that regard are documented in the Information and Communication Security Audit Guide published by the Digital Transformation Office. Furthermore, the Critical Infrastructures National Test Bed Centre, which hosts studies to ensure the security of electricity distribution and water management infrastructure, was inaugurated with the cooperation of related parties in Türkiye. The Centre, where energy and water management systems are modelled, is designed to present a working environment in order to search for and develop protective and preventive solutions related to the security of critical infrastructure and to contribute to the cybersecurity ecosystem. Developing projects to improve the security of information an d cybersecurity is one of the main responsibilities of the Digital Transformation Office as defined by the articles incorporated by Presidential Decree No. 48 published in Official Gazette 24/34 22-08761