e. that usage fees shall be determined to the extent necessary to ensure the most effective use of frequencies; f. that obligations assumed in a selection process are fulfilled; g. that obligations under international agreements on use of frequencies are taken into consideration. PTA may, furthermore, attach the following conditions in assigning numbers: a. that assignment of rights to use numbers shall apply only to certain services; b. on the supply of a service; c. that use of numbers is effective and efficient; d. that number portability is offered; e. that general public directory information is provided; f. that the period of validity of the rights shall be limited and subject to any changes in the national numbering plan; g. that the licensee pay usage fees; h. that obligations assumed in a selection process are fulfilled; i. that obligations under international agreements on use of numbers are taken into consideration. Article 11 Procedure for assigning of rights to use frequencies and numbers PTA shall decide on rights to use frequencies and numbers. Such a decision shall be taken, notified and made public as soon as possible after receipt of an application. A decision shall be available within three weeks in the case of numbers assigned for specific purposes within the national numbering plan and within six weeks in the case of frequencies assigned for specific purposes within the national plan. Applicants for limited rights may be required to submit satisfactory information on their ownership, financial situation and proposed activities, as well as other information deemed necessary for assessment of their applications. Assignment of rights to use numbers and frequencies may be decided by competitive selection procedures. Open procedures shall as a rule be used and the conditions for tendering, in the case of frequencies, shall include a specification of the minimum service area. The Minister of Communications may decide that assignment shall take place following an auction under special circumstances. If a decision is taken to hold selection procedures or an auction for assignment of numbers, the time limits for the procedure as provided for in the first paragraph may be extended by three weeks. If a decision is taken to hold selection procedures or an auction for assignment of frequencies, the time limits for the procedure as provided for in the first paragraph may be extended, but no longer than by eight months. Article 12 Changes to rights 8/34