Chapter 2 • The Major Universal Human Rights Instruments and the Mechanisms for Their Implementation 4. Instruments adopted by the United Nations Congress on the Prevention of Crime and the Treatment of Offenders Interpretative guidance as to the meaning of international legal standards can also be sought in the following non-binding instruments which were adopted by the various United Nations Congresses on the Prevention of Crime and the Treatment of Offenders: v Standard Minimum Rules for the Treatment of Prisoners, 1955; v Basic Principles on the Independence of the Judiciary, 1985; v Basic Principles on the Use of Force and Firearms by Law Enforcement Officials, 1990; v Basic Principles on the Role of Lawyers, 1990; and v Guidelines on the Role of Prosecutors, 1990. However, since these instruments will be examined in some depth in other chapters of this Manual, they will not be dealt with further in this chapter. 5. United Nations Extra-Conventional Mechanisms for Human Rights Monitoring In addition to the international treaty mechanisms, the United Nations has established what are referred to as “special procedures” to deal with especially serious human rights violations and to review petitions from individuals and NGOs. These procedures, which are established within the framework of the United Nations Commission on Human Rights, are aimed at establishing constructive cooperation with the Governments concerned in order to redress violations of human rights. There are basically two categories, namely, the thematic and country procedures on the one hand, and the 1503 procedure on the other. Human Rights in the Administration of Justice: A Manual on Human Rights for Judges, Prosecutors and Lawyers 67