(e) (f) keeps the cost of changing any of the telecommunications systems in order to accommodate the number plan within reasonable limits; and minimise any inconvenience that may be caused by implementation of the numbering plan to a licensee and to persons using the telecommunications systems. (2) The numbering scheme of each licensee shall comply with the Commission's guidelines concerning the implementation of the national numbering plan. (3) The Commission may in assigning or allocating numbers to licensees charge fees for such allocation or assignment. (4) For purposes of this Part – “numbering plan” means the method of assigning NNX codes to provide a unique telephone addresses or identities to a user-network interface. PART X - POSTAL AND COURIER SERVICES Application. 64. The Regulations in this Part shall apply to all postal service licensees. Interpretations. 65. requires- In this Part, unless the context otherwise "basic postal services" means reserved postal services such as postal stamps, private letterboxes and acceptance, conveyance and delivery of letters weighing up to 350 grams; "commemorative stamps issue" means the issuance of postage stamps as a mark of honour to events or matters of national or international importance and mainly used for philatelic purposes with a validity period of five years from the date of issue; 50