2. Extraconventional (Charter-based) mechanisms 67. A number of procedures have been established under the authority granted by the Charter of the United Nations to the Economic and Social Council and, through it, to its subsidiary Commission on Human Rights and Subcommission on the Promotion and Protection of Human Rights. These procedures may be either confidential or public. The so-called "1503 procedure" is the confidential one, whereas the various thematic or country-orientated special rapporteurs and working groups of the Commission on Human Rights operate publicly under the authority of Economic and Social Council resolution 1235 (XLII) of 6 June 1967. It should be noted that the confidential procedure has been rendered partially obsolete by the development of the public procedure discussed below. (a) Confidential procedure 68. The confidential procedure was established pursuant to Economic and Social Council resolution 1503 (XLVIII) of 27 May 1970 and amended by its resolution 2000/3 of 16 June 2000. Under the "1503 procedure", the Commission on Human Rights has the mandate to examine a consistent pattern of gross and reliably attested systematic violations of human rights and fundamental freedoms occurring in any country of the world. 69. The Secretariat, together with the chairperson of the Subcommission's Working Group on Communications, screen complaints from both individuals and groups. If the communication is not prima facie ill-founded and the individual has exhausted all domestic remedies, it will be acknowledged and forwarded to the Government concerned for comment in a confidential manner. After the initial screening, the Working Group on Communications meets to assess complaints and any replies received from Governments. It forwards to the Commission on Human Rights' Working Group on Situations any situation that reveals a consistent pattern of gross and reliably attested human rights violations. The Working Group on Situations decides whether, in the light of all the material from the previous stages of the process, the situation referred to it appears to reveal a situation of systematic human rights violations. In that case it may forward a situation to the Commission on Human Rights, usually with specific recommendations. Otherwise, the Working Group may decide to keep a situation pending before it or close the file. 70. The Commission on Human Rights considers in closed session the situations referred to it by its Working Group on Situations. Representatives of the Governments concerned may also be present at this point. The Commission may decide to keep a situation under review; it may appoint an independent expert on the matter to report confidentially to the Commission (in 2002 an independent expert was appointed to study the human rights situation in Liberia); it may discontinue the matter if no further consideration is warranted; or it may take up the same matter under the public procedure governed by resolution 1235 (XLII) of the Economic and Social Council. If it wishes, the Commission may also make recommendations to its parent body, the Economic and Social Council. After the Commission has considered the situations before it, the chairperson announces at a public meeting the 21