An electronic air ticket, also known as e-ticket, can be used in place of the formal paper ticket during flights today. It is the digital ticket equivalent of a paper ticket. While majority airlines issue e-tickets, some airlines use paper tickets with additional charges. When a reservation is confirmed, the airline keeps a record of the booking in its computer reservations system. Customers can print out or may be provided with a copy of a e-ticket itinerary receipt which contains the record locator or reservation number and the e-ticket number. Passengers with e-tickets are required to check-in at the airport for a flight in the usual manner, except that they may be required to present an e-ticket itinerary receipt or personal identification, such as a passport, or credit card. Besides providing itinerary details, an e-ticket itinerary receipt also contains: - An official ticket number - 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.