(1) Where the Agency considers that interest in a particular radio frequency could exceed availability and thereby prevent its efficient use, it shall publish a public call to acquire the opinions of interested parties concerning the conditions of use of these frequencies, particularly regarding limiting the number of beneficiaries of decisions allocating radio frequencies. The Agency shall, at regular intervals of time which may not exceed three years, check whether a new public call as referred to in the preceding paragraph is required. The Agency must always publish such a public call when it receives an initiative for a public invitation to tender from any party interested in using specific radio frequencies. (2) The Agency shall, in the public call, lay down the deadline for the acquisition of opinions from interested parties, which may not be shorter than 30 days, and specify those issues regarding which it wishes to acquire the opinions of interested parties. The Agency must maintain the confidentiality of any proposals from interested parties regarding the level of the fee for radio frequencies. (3) Where the Agency determines, on the basis of the response of interested parties and of other relevant information at its disposal, that specific radio frequencies will not be made available to all interested parties, it must carry out a public invitation to tender prior to issuing decisions allocating radio frequencies. In the opposite case, the Agency shall issue decisions allocating radio frequencies under the provisions of the act governing the general administrative procedure. Article 37 (application of provisions in the implementation of a public invitation to tender) (1) With the exception of the provisions on exclusion, the provisions of the act governing the general administrative procedure shall not be applied to the public invitation to tender procedure itself. (2) A public invitation to tender shall be conducted by a special impartial commission (hereinafter: commission) appointed by the director of the Agency, to which persons not employed by the Agency may also be appointed. (3) The provisions on the exclusion of an official shall also be applied to members of the commission who are not officials employed by the Agency. Article 38 (decision on the initiation of a public invitation to tender) (1) A public invitation to tender shall commence on the basis of an Agency decision, which must contain at least the following: 1. a precise indication of the radio frequencies that are the subject of the public invitation to tender, the radiocommunications services to be provided through the use of these radio frequencies, and the areas or locations in which these radio frequencies are to be used; 2. the conditions, requirements and qualifications to be met by tenderers, which must comply with the relevant legislation and spatial planning documents in force; 3. criteria for the selection of the most favourable tender, the method of their application, and any other restrictions to be taken into account in the evaluation of tenders; 4. the minimum fee for the efficient use of a limited natural resource and the method of payment (one-off payment, annual payment), unless the public invitation to tender relates to radio frequencies for the provision of analogue broadcasting services; 5. the deadline by which tenderers may submit tenders and the method applying to their submission (date, time, address, code); 6. the address, place, date and time of the public opening of tenders;