21 GROPPERA RADIO AG AND OTHERS v. SWITZERLAND JUDGMENT adapt his behaviour to them - even after consulting a lawyer, if necessary. The applicants added that international telecommunications law was binding only on the States parties to the instruments in question; as Groppera Radio AG’s transmitter came under Italian jurisdiction, any problem with applying that law therefore had to be resolved at inter-State level, if need be by resorting to the machinery provided for in Article 50 of the International Telecommunication Convention. In short, they claimed that the interference complained of was not "prescribed by law". 66. The Commission reached a similar conclusion. It noted that neither Article 78 § 1 (a) of the 1983 Ordinance nor the decision taken by the Zürich area telecommunications office of the PTT on 21 March 1984 (see paragraphs 17 and 19 above) mentioned any particular rule of international telecommunications law. The Commission also referred to the Swiss Federal Court’s and the Italian Constitutional Court’s judgments of 14 June 1985 and 6 May 1987 (see paragraphs 25 and 32 above) in order to advance the view that the question whether Groppera Radio AG was validly in possession of a "licence" within the meaning of number 2020 of the Radio Regulations (see paragraph 35 above) had not been resolved. To hold that in the instant case the persons concerned could know what the legal basis of the measure affecting Sound Radio was would amount to giving the authorities a quasi-discretionary power to ban any programme alleged to be contrary to public international law. 67. The Government submitted that, on the contrary, the national and international rules in issue satisfied the criteria of precision and accessibility identified in the Convention institutions’ case-law. On the first point the Government argued that the decision taken on 31 July 1984 by the national head office of the PTT referred to Article 78 § 1 (a) of the 1983 Ordinance and to several specific provisions of international telecommunications law (Article 35 of the International Telecommunication Convention and numbers 584 and 2666 of the Radio Regulations). They also emphasised the monistic concept followed in the Swiss legal system; this allowed individuals to rely on rules of international law in order to assert rights and obligations vested in or incumbent on the authorities or other individuals. Lastly, they stated that the applicants were by no means unaware of the international rules applicable in Switzerland. This was evidenced by two documents: the letter of 29 January 1980 from the PTT’s national head office to all licensed community-antenna companies in the area in which Radio 24 (Sound Radio’s predecessor) could be received and the Federal Court’s judgment of 12 July 1982 in the case of Radio 24 Radiowerbung Zürich AG gegen Generaldirektion PTT (Judgments of the Swiss Federal Court, vol. 108, Part 1b, p. 264). These documents had clearly defined a legal position which the 1983 Ordinance expressed in legislative form.