[Code of Federal Regulations] [Title 14, Volume 4] [Revised as of January 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR221.53] [Page 65-66] TITLE 14--AERONAUTICS AND SPACE CHAPTER II--OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) PART 221_TARIFFS--Table of Contents Subpart F_Requirements Applicable to All Statements of Fares and Charges Sec. 221.53 Proportional fares. (a) Definite application. Add-on fares shall be specifically designated as ``add-on'' fares on each page where they appear. (b) A tariff may provide that fares from (or to) particular points shall be determined by the addition of add-ons to, or the deduction of add-ons from, fares therein which apply from (or to) a base point. Provisions for the addition or deduction of such add-ons shall be shown either directly in connection with the fare applying to or from the base point or in a separate provision which shall specifically name the base point. The tariff shall clearly and definitely state the manner in which such add-ons shall be applied. [[Page 66]] (c) Restrictions upon beyond points or connecting carriers. If an add-on fare is intended for use only on traffic originating at and/or destined to particular beyond points or is to apply only in connection with particular connecting carriers, such application shall be clearly and explicitly stated directly in connection with such add-on fare.