E/CN.4/2001/83 page 8 protection of the right to non-discrimination. The Covenant specifically recognizes the following basic rights: right to life (art. 6), protection against torture and cruel, inhuman or degrading treatment or punishment (art. 7), protection against slavery (art. 8) and rights to liberty and security of person (art. 9), freedom of movement (art. 12) and freedom of thought, conscience and religion (art. 18). 24. Article 12 of the Covenant contains various provisions relating to the right to freedom of movement. The Covenant does not recognize the right of aliens to enter or reside in the territory of a State party, but, in certain circumstances, an alien may enjoy the protection of the Covenant even in relation to entry or residence, for example, when considerations of non-discrimination, prohibition of inhuman treatment and respect for family life arise, as stated by the Human Rights Committee at its twenty-seventh session in 1986 in its General Comment No. 15. At its sixty-seventh session, the Committee adopted General Comment No. 27 on liberty of movement and freedom to choose residence. The Special Rapporteur shares the Committee’s opinion that it is important for States parties to indicate the circumstances in which they treat aliens differently from their nationals in this regard and how they justify this difference in treatment. 25. The International Covenant on Economic, Social and Cultural Rights, which has so far been ratified by 143 States, recognizes the following rights, which relate directly to the topic of our study: the right to work (art. 6), the right to just and favourable conditions of work (art. 7), the right to form and join trade unions and the right to strike (art. 8), the right to an adequate standard of living (art. 11), the right to the highest attainable standard of physical and mental health (art. 12) and the right to education (art. 13). 26. The International Convention on the Elimination of All Forms of Racial Discrimination, which has, at the time of writing of this report, been ratified by 156 States, condemns racial discrimination, i.e. any distinction, exclusion, restriction or preference based on race, colour, descent, or national or ethnic origin which has the purpose or effect of nullifying or impairing the recognition, enjoyment or exercise, on an equal footing, of human rights and fundamental freedoms in the political, economic, social, cultural or any other field of public life. The Convention provides for the possibility of treatment differentiating between citizens and non-citizens, but, as between non-citizens, States may not discriminate against any particular nationality. In addition, the Committee on the Elimination of Racial Discrimination affirms that such a distinction between citizens and non-citizens must not be interpreted as in any way affecting the rights and freedoms recognized in other instruments. The Convention requires States to condemn racial discrimination and pursue policies to eliminate it. It condemns racial segregation and apartheid, as well as propaganda and organizations which are based on ideas of the superiority of one race, the promotion of racial hatred and incitement to racial discrimination. Article 5 of the Convention contains a list of rights which must be enjoyed without distinction as to race, colour or national or ethnic origin. 27. Article 3 of the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, which has so far been ratified by 123 States, prohibits the expulsion, return or extradition of a person to another State where there are substantial grounds for believing that he would be in danger of being subjected to torture.