The right to equality and the prohibition of discrimination is normally formulated with respect to specific grounds. In the Charter of the United Nations, these are race, sex, language, and religion. The list was expanded in the Universal Declaration of Human Rights, where it was also prefaced by the words ‘such as’ thereby recognising that distinctions based upon unenumerated categories might also be encompassed. These might include age, disability, and sexual orientation, for example. International law also provides special protection for children. Related to non-discrimination is the distinct field of protection of minorities, which are identifiable on the basis of ethnicity, language, and religion, and of indigenous peoples.