Article 30 specifies that "the use of languages spoken in Belgium is optional; only the law can rule on this matter, and only for acts of the public authorities and for legal matters." For those public authorities, there is extensive language legislation concerning Dutch, French and German, even though the Belgian Constitution does not explicitly mention which languages enjoy official status. Article 4 divides the country into linguistic areas, which form the basis of the federal structure: "Belgium has four linguistic areas: The French-speaking area, the Dutch-speaking area, the bilingual area of Brussels Capital, and the German-speaking area."