The rights of use for numbering resources shall be granted through open, objective, transparent, non-discriminatory and proportionate procedures.
When granting rights of use for numbering resources, national regulatory or other competent authorities shall specify whether those rights can be transferred by the holder of the rights, and under which conditions.
Where national regulatory or other competent authorities grant rights of use for numbering resources for a limited period, the duration of that period shall be appropriate for the service concerned with a view to the objective pursued, taking due account of the need to allow for an appropriate period for investment amortisation.