The Optional Protocol to the Convention on the Elimination of All Forms of Discrimination against Women (OP-CEDAW) is an international treaty which establishes complaint and inquiry mechanisms for the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW). Parties to the Protocol allow the Committee on the Elimination of Discrimination against Women to hear complaints from individuals or inquire into 'grave or systematic violations' of the Convention. The Protocol has led to a number of decisions against member states on issues such as domestic violence, parental leave and forced sterilization, as well as an investigation into the systematic killing of women in the Mexican city of Ciudad Juárez, Chihuahua. The Protocol was adopted by the United Nations General Assembly on 6 October 1999, and in force from 22 December 2000. As of September 2017, the Protocol has 80 signatories and 109 parties. In 1979, the United Nations General Assembly adopted the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW). The Convention outlawed discrimination against women, but did not include any mechanism by which this prohibition could be legally enforced. An individual complaints mechanism was suggested during the original drafting of CEDAW, but was rejected at the time. Fifteen years later, the Vienna Declaration and Programme of Action of the 1993 World Conference on Human Rights suggested that new procedures were needed to implement the Convention, and suggested a 'right of petition'. An independent expert group produced a draft in 1994, containing a complaint procedure and an inquiry procedure, and this was adopted for further study by the Committee on the Elimination of Discrimination against Women in early 1995. The idea of an Optional Protocol was further endorsed by the Fourth World Conference on Women in 1995, which called for 'the elaboration (of) a draft optional protocol to the Women's Convention that could enter into force as soon as possible.' In March 1996 the Commission on the Status of Women established an open-ended working group to produce a formal draft. This reported back after three years of deliberation in early 1999. The Optional Protocol was adopted by the UN General Assembly on 6 October 1999. The Convention on the Elimination of All Forms of Discrimination against Women outlaws discrimination on the basis of gender, and obliges its parties to repeal discriminatory laws and guarantee equality in the fields of health, employment, and education. The Optional Protocol is a subsidiary agreement to the Convention. It does not establish any new rights, but rather allows the rights guaranteed in the Convention to be enforced. Articles 1–7 create an individual complaints mechanism similar to those of the First Optional Protocol to the International Covenant on Civil and Political Rights, Optional Protocol to the Convention on the Rights of Persons with Disabilities and Article 14 of the Convention on the Elimination of All Forms of Racial Discrimination. Parties agree to recognise the competence of the Committee on the Elimination of Discrimination against Women to consider complaints 'by or on behalf of' individuals or groups who claim their rights under the Convention have been violated. If a complaint is submitted on behalf of a victim, then this requires their consent, unless the submitter can justify acting without it. What constitutes 'justification' in such a case is up to the Committee. The ability for complaints to be submitted on behalf of victims is seen as vital in allowing NGOs such as women's organizations and human rights groups to use the Protocol to enforce the Convention. Complainants must have exhausted all domestic remedies, and anonymous complaints and complaints referring to events which occurred before the country concerned joined the Optional Protocol are not permitted. The Committee can request information from and make recommendations to a party, though these are not binding.