An official ticket number (including the airline's 3-digit ticketing code,[2] a 4-digit form number, a 6-digit serial number, and sometimes a check digit) Carriage terms and conditions (or at least a reference to them) Fare and tax details, including fare calculation details and some additional data such as tour codes. The exact cost might not be stated, but a "fare basis" code will always identify the fare used. A short summary of fare restrictions, usually specifying only whether change or refund are permitted but not the penalties to which they are subject Form of payment Issuing office Baggage allowance