30 GORZELIK AND OTHERS v. POLAND JUDGMENT the Chamber rightly pointed out, such a definition would be very difficult to formulate. In particular, the notion is not defined in any international treaty, including the Council of Europe Framework Convention (see paragraph 62 of the Chamber's judgment and paragraph 46 above and, for example, Article 27 of the United Nations International Covenant on Civil and Political Rights, Article 39 of the United Nations Convention on the Rights of the Child and the 1992 United Nations Declaration on the Rights of Persons Belonging to National or Ethnic, Religious and Linguistic Minorities). Likewise, practice regarding official recognition by States of national, ethnic or other minorities within their population varies from country to country or even within countries. The choice as to what form such recognition should take and whether it should be implemented through international treaties or bilateral agreements or incorporated into the Constitution or a special statute must, by the nature of things, be left largely to the State concerned, as it will depend on particular national circumstances. 68. While it appears to be a commonly shared European view that, as laid down in the preamble to the Framework Convention, “the upheavals of European history have shown that the protection of national minorities is essential to stability, democratic security and peace on this continent” and that respect for them is a condition sine qua non for a democratic society, it cannot be said that the Contracting States are obliged by international law to adopt a particular concept of “national minority” in their legislation or to introduce a procedure for the official recognition of minority groups. 69. In Poland the rules applicable to national or ethnic minorities are not to be found in a single document, but are divided between a variety of instruments, including the Constitution, electoral law and international agreements. The constitutional guarantees are afforded to both national and ethnic minorities. The Constitution makes no distinction between national and ethnic minorities as regards their religious, linguistic and cultural identities, the preservation, maintenance and development of their language, customs, traditions and culture, or the establishment of educational and cultural institutions (see paragraph 37 above). In contrast, electoral law introduces special privileges only in favour of “registered organisations of national minorities” (see paragraph 41 above). It does not give any indication as to the criteria a “national minority” must fulfil in order to have its organisation registered. However, the Court considers that the lack of an express definition of the concept of “national minority” in the domestic legislation does not mean that the Polish State was in breach of its duty to frame law in sufficiently precise terms. Nor does it find any breach on account of the fact that the Polish State chose to recognise minorities through bilateral agreements with neighbouring countries rather than under a specific internal procedure. The