II. Definitions and cross-cutting issues Cross-cutting issues and principles It is also important to take note of the cross-cutting issues and principles that should be considered and addressed when tackling statelessness in any country or situation to ensure the effectiveness, acceptance and sustainability of proposed solutions. These include: the principle of non-discrimination; the age, gender and diversity approach; and the participation of stateless persons in decision-making processes. The principle of non-discrimination The principle of non-discrimination has been enshrined in various international human rights instruments, and the respective human rights bodies created under the different treaties are monitoring States’ compliance. The OSCE has also committed to eradicating discrimination and promoting tolerance and non-discrimination in various documents (see Chapter IV). Despite this, discrimination on the basis of ethnicity, race, religion, gender11, language or disability is a recurrent cause of statelessness. In fact, the majority of the world’s known stateless populations belong to minority groups that experience discrimination. Instances of denial, loss and deprivation of nationality on discriminatory grounds that lead to statelessness continue to occur across a range of countries worldwide. To ensure that State authorities refrain from denying or depriving people of nationality on discriminatory grounds, States should introduce nondiscriminatory provisions in their constitutions and nationality laws and uphold the principle of non-discrimination when implementing such laws. There needs to be adequate supervision of compliance with such provisions, including through complaint mechanisms, the possibility of judicial review, and restitution of nationality. UNHCR has a specific mandate to identify, prevent and reduce statelessness and to protect stateless persons. However, OSCE actors, such as ODIHR and HCNM, also engage States to help them effectively comply with their legal obligations vis-à-vis individuals or groups experiencing discrimination and in need of protection. 16