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Glossary for the airline industry

From A-Z, this glossary covers definitions and explanations for common airline industry terminology.

inbound travel

1. (non-directional fares) All fare components within the pricing unit that occur after the point of turnaround (after the furthest geographical fare break point.)

2. (directional fares) All fare components within the pricing unit that are selected in the opposite direction of the passenger's travel.


Portion of a query to gather records that meet certain criteria. Results give you a current picture of your database.

inclusive table

A table used to identify specific items (such as countries, cities, fare classes, and rule numbers) that will produce an identical action or result.

indirect channel

The process of pricing and booking tickets via a third-party intermediary, usually a travel agency or travel management company. These processes rely on industry intermediated schedule and fare data to run, and constitute the majority of bookings worldwide.

Industry Sales Record

A daily process that takes the three different sales data formats (TCN 4.05, ARC CAT, and BSP HOT V20) and combines them into a single data feed.


Infant without a seat (usually under age 2).


A viewing facility that allows the display of records in the database file without updating. A carrier using this facility can view all its own records and the public records of all other carriers. An ATPCO analyst can view all records of all carriers.


Infant occupying a seat (usually under age 2).


The written description and justification to ATPCO from a publishing carrier describing desired changes to a fare rule, add-on, footnote, routing, or to any other product. See also filing advice.

interface standards

Technical standards that document file specifications and data element attributes.


A ticketed reservation that involves multiple carriers. Used in conjunction with other words such as interline itinerary, interline reservation, or interline point.

intermediate point

A ticketed point between the terminal points of the fare component.


Travel between any two or more sovereign states.

international fares

Fares involving travel between two or more sovereign states, or travel within a sovereign state other than US/CA and between the United States or Canada (including ATPCO AllFares data).

international tariff

A tariff whose geographic application is other than within or between the United States and Canada. This term is mostly used for tariffs to/from US/CA. AllFares tariffs are also international, but that term is used only for travel that does not include US/CA.


The ability of data to be used in different systems, among different partners, and for different purposes while still producing consistent results.


The transferring from different flights services on the same carrier, or the transferring of services on the primary carrier only.


A count of the number of seats a carrier has available for sale at any given time for any given flight. Inventory messaging occurs directly between carriers and the GDSs and is connected to the fare and rule data via ATPCO's RBD product. Airlines manage inventory databases with yield management systems. Fare quotation systems query inventory databases directly for up to date availability information for use in pricing.


Industry Sales Record.


Interline Staff Travel Agreement