of the Council of Europe has adopted a recommendation that provides more detail on what facilitated naturalisation may require in the context of statelessness, including relaxation of conditions and fees in certain circumstances.331 The only treaty establishing general norms on acquisition of nationality based on habitual residence is the 1997 European Convention on nationality, which requires that states parties provide for “the possibility of naturalisation of persons lawfully and habitually resident on its territory”, and establishes a maximum period of ten years’ residence. The Protocol to the African Charter on the Right to a nationality establishes that acquisition based on legal residence should be possible, including for children born and resident in the territory during childhood, but does not specify a time limit. There is no agreed definition of the nature of the habitual residence that would qualify a person to apply for naturalisation. The European Convention on nationality and the Protocol to the African Charter on the Right to a nationality permit the requirement for such residence to be lawful, as provided in the laws of many states. However, this condition may be impossible to fulfil for those without identity documents or a recognised existing nationality. Article 1 of the 2006 European Convention on the Avoidance of Statelessness in relation to State Succession defines “habitual residence” differently, as “stable factual residence”; this interpretation is endorsed by the UNHCR Guidelines, which note that the 1961 Convention does not permit an application for the acquisition of nationality by individuals who would otherwise be stateless to be conditional upon lawful residence. In some contexts of statelessness, habitual residence may also be factually difficult to determine. In its guidelines on avoiding statelessness among children, UNHCR notes that: It follows from the factual character of “habitual residence” that in cases where it is difficult to determine whether an individual is habitually resident in one or another State, for example due to a nomadic way of life, such persons are to be considered as habitual residents in both States.332 The Protocol to the African Charter on the Right to nationality includes a specific article on the situation of people whose habitual residence is in doubt, including those who follow a pastoralist or nomadic lifestyle and whose movements cross borders, or who are members of cross-border communities, setting out a range of “appropriate connections” on the basis of which nationality might be recognised. In general, preferential naturalisation provisions facilitating acquisition by certain population groups are not regarded as problematic.333 Some language and cultural assimilation requirements for naturalisation are also seen as reasonable. International treaty bodies have, however, criticised some states for imposing discriminatory conditions for naturalisation, including onerous language requirements, or exclusions based on race or ethnicity.334 In its General Recommendation on discrimination against non-citizens, the CERD Committee urged states to “ensure that particular groups of non-citizens are not discriminated against with regard to access to citizenship or naturalisation, and to pay due attention to possible barriers to naturalisation that may exist for long-term or permanent residents.”335  The Human Rights Committee found that Denmark’s refusal of naturalisation to a person with learning disabilities who could not fulfil the language test was in violation of article 26 of the ICCPR on non-discrimination and equality before the law, stating that: [N]either the Covenant nor international law in general spells out specific criteria for the granting of citizenship through naturalisation and that States are free to decide on such criteria. However, when adopting and implementing legislation, States parties’ authorities must respect the applicants’ rights enshrined in article 26. The Committee recalls in this respect that article 26 requires reasonable and objective justification and a legitimate aim for distinctions that relate to an individual’s characteristics enumerated in article 26, including “other status” such as disability.336  In a case brought against Latvia by a “Latvian non-citizen”—a status granted to former Soviet citizens who remained resident in the territory after the break-up of the Soviet Union and who did not acquire Latvian citizenship automatically—the European Court of Human Rights found that the denial of his application for Council of Europe Committee of Ministers Recommendation No. R(99)18 on the avoidance and reduction of statelessness, 15 September 1999, https:// www.refworld.org/docid/510101e02.html. 331 332 UNHCR, Guidelines on Statelessness No. 4, supra n 102, para. 42. Proposed Amendments to the Naturalisation Provision of the Constitution of Costa Rica, Inter-American Court of Human Rights, Advisory Opinion OC-4/84, 19 January 1984, https://www.refworld.org/cases,IACRTHR,44e492b74.html. 333 334 Spiro, “A New International Law of Citizenship”, supra n 286, at pp.725-728. General Recommendation XXX of the Committee on the Elimination of Racial Discrimination on Discrimination against Non-citizens, 5 August 2004, https:// www.refworld.org/docid/45139e084.html, included within the report The Rights of Non-citizens, Office of the UN High Commissioner for Human Rights, 2006, https://www.ohchr.org/en/publications/special-issue-publications/rights-non-citizens. 335 Q. v. Denmark, Communication No. 2001/2010, Human Rights Committee, Views of May 19, 2015, UN Doc CCPR/C/113/D/2001/2010, para. 7.3., https:// digitallibrary.un.org/record/795228?ln=en. 336 U N H C R | L I T I G AT I N G T H E R I G H T T O A N AT I O N A L I T Y: A G U I D E F O R P R AC T I T I O N E R S 77