44 Report of the International Law Commission on the work of its fifty-first session sor State habitually resident in the territory of a particular successor State were not attributed the latter’s nationality. The legislation of the successor States contained separate provisions on the acquisition of their nationality by such persons.130 In those instances where they were offered the possibility to acquire the nationality of their State of residence nearly all took advantage of such offer.131 Where such possibility was considerably limited, serious difficulties arose in practice.132 (6) Having examined State practice, including most recent developments, the Commission reaffirmed the importance of the criterion of habitual residence and decided to resort to “citizenship” of a constituent unit of a State only with respect to persons residing outside the territory of a particular successor State. In the same vein, provision 8.a of the Venice Declaration confirmed the rule that “[i]n all cases of State succession, the successor State shall grant its nationality to all nationals of the predecessor State residing permanently on [its] territory”.133 (7) Article 22, subparagraph (b) sets out rules for the attribution of the nationality of a successor State to per- sons concerned having their habitual residence outside its territory. (8) The obligation of a successor State to attribute its nationality to such persons, as well as its right to do so, is of course limited by the provisions of article 8, as indicated in the chapeau of subparagraph (b). Subparagraph (b) (i) deals with persons concerned who have their habitual residence either in a third State or in another successor State. The criterion used is “an appropriate legal connection with a constituent unit of the predecessor State” that has become part of a particular successor State. It goes without saying that this criterion can only be used where a bond of a legal nature between constituent units of the predecessor State and persons concerned existed under the internal law of that State. As discussed above, this was mostly the case of certain federal States.134 (9) Where subparagraph (i) is applicable, the majority of persons concerned having their habitual residence outside the territory of a particular successor State will fall under this category and subparagraph (ii) will come into play rather exceptionally, i.e. with respect to persons not already covered by subparagraph (i). (Footnote 129 continued.) of the Former Yugoslav Republic of Macedonia of 27 October 1992 (No. 67/1992), Sluzben vesnik na Republika Makedonija (Official Gazette of the Republic of Macedonia) (see also C. Batchelor, P. Leclerc and B. Schack, Citizenship and Prevention of Statelessness Linked to the Disintegration of the Socialist Federal Republic of Yugoslavia (UNHCR, 3 April 1997), p. 21); and article 27 of the Decree Having the Force of Law on the Citizenship of the Republic of Bosnia and Herzegovina of 7 October 1992 (No. 18/1992, as amended by No. 11/1993), Sluzbeni list Republike Bosne i Hercegovine (Official Gazette of the Republic of Bosnia and Herzegovina) (ibid., p. 27). 130 Thus, article 40 of the Law on Citizenship of the Republic of Slovenia, of 5 June 1991 (footnote 129 above) provided that “[a] citizen of another republic [of the Yugoslav Federation] that had permanent residence in the Republic of Slovenia on the day of the Plebiscite on the independence and autonomy of the Republic of Slovenia on 23 December 1990 and is actually living there, can acquire citizenship of the Republic of Slovenia, on condition that such a person files an application with the administrative organ competent for internal affairs of the community where he resides.” Article 30, paragraph 2, of the Law on Croatian Citizenship of 26 June 1991 (see footnote 46 above) provided that any person belonging to the Croat people who did not hold Croat nationality on the day of the entry into force of the Law but who could prove that he had been legally resident in the Republic of Croatia for at least 10 years, would be considered to be a Croat citizen if he supplied a written declaration in which he declared that he regarded himself as a Croat citizen. Article 29 of the Decree Having the Force of Law on the Citizenship of the Republic of Bosnia and Herzegovina of 7 October 1992 (see footnote 129 above), as amended in April 1993, provided that all citizens of the former Socialist Federal Republic of Yugoslavia resident on the territory of Bosnia and Herzegovina as of 6 April 1992 automatically became nationals of Bosnia and Herzegovina (see Batchelor, Leclerc and Schack, op. cit. (ibid.), p. 27). 131 For instance, the practice of the Czech Republic indicates that nearly all persons concerned habitually resident in its territory who did not acquire Czech nationality ex lege on the basis of the criterion of “citizenship” of the constituent unit of the federation acquired such nationality via optional application. Thus, some 376,000 Slovak nationals acquired Czech nationality in the period from 1 January 1993 to 30 June 1994, mostly by option under article 18 of Law No. 40/1993 of 29 December 1992 on acquisition and loss of citizenship of the Czech Republic (Report of the experts of the Council of Europe . . . (footnote 35 above), appendix IV). The outcome was not substantially different from what would have resulted from the use of the criterion of habitual residence (ibid., para. 22 and note 7). 132 Batchelor, Leclerc and Schack, op. cit. (footnote 129 above), pp. 4 et seq. 133 See footnote 16 above. (10) Subparagraph (ii) only deals with persons concerned who have their habitual residence in a third State, i.e. who, on the date of the succession of States, had their habitual residence outside the territory of the predecessor State. The criteria referred to in subparagraph (ii) are those which were most often used in State practice, namely place of birth and place of the last habitual residence in the territory of the predecessor State. The Commission, however, did not want to exclude the use of other criteria, as indicated by the phrase “or having any other appropriate connection with that successor State”. It emphasized, at the same time, that the use of any such criteria must be consistent with the general obligation of non-discrimination under article 15. (11) Article 22 does not address the question of the mode of attribution by the successor State of its nationality. A successor State may fulfil its obligation under this provision either by means of automatic attribution of its nationality to persons concerned or by providing for the right of these persons to acquire such nationality upon option. (12) The application of the criteria in article 22 may result in a person concerned being qualified to acquire the nationality of more than one successor State. In such case, the attribution of nationality will depend on the option of such person, as indicated in the chapeau of article 22. Moreover, subparagraph (b) is subject to the provision in article 8 whereby a State is prohibited from attributing its nationality to persons concerned having their habitual residence outside its territory against their will. Accordingly, the obligation of a State under subparagraph (b) is to be implemented either through an “opting-in” procedure or by ex lege attribution of its nationality with an option to decline (“opting-out” procedure). (13) Paragraph 1 of article 23 provides for the right of option of persons concerned who are qualified to acquire 134 See footnote 128 above.