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Glossary for the airline industry

Definitions and explanations of common terms in the airline industry


Application Programming Interface


A small application that performs one specific task, typically running under the control of a larger application, such as a web browser.


The fares (or rates) that may be combined with an international fare (or rate) published to a gateway to create a through-fare. Arbitraries may not be sold separately for travel and are usually published between points within the same country. Also referred to as add-ons or proportionals.

arbitrary bucket

The text that defines fare class combinability. Arbitrary buckets may be fare class specific, generic (such as A***** and B*****), or default (******). The default bucket is often referred to as the negative or six-star bucket.

arbitrary zone

Applicable to international tariffs only, a zone is a component of an add-on record that defines the geographic area of the published fare with which the add-on will construct.


Airlines Reporting Corporation.


IATA divides the world into three areas, also referred to as Traffic Conferences (TC): Area 1: Western Hemisphere Area 2: Europe, Africa, Middle East Area 3: Asia, Pacific


Available seat kilometers; an industry measure of capacity, calculated by multiplying the total number of seats by the distance of the flight.


Available seat miles; an industry measure of capacity, calculated by multiplying the total number of seats by the distance of the flight.

assembled data feed

An ATPCO subscription that provides merged pricing and restrictions data to support airline pricing, revenue management, and intelligence processes. This structured dataset calculates total price values and simplifies data aggregation (and analysis) by combining the applicable fare rules with the price points.

assortment optimization

A dynamic pricing method where the system selects one or more prices from a finite menu of possible price points. Each price point may be associated with various rules or restrictions that determine how or when that price can be selected. The menu of price points may be updated periodically, but there is only a limited and discrete set of possible prices that can be selected at any given time. The selection of a price from the menu could be made infrequently or, at the limit, on a transaction-by-transaction basis.


Airline Tariff Publishing Company. A corporation owned by various airlines formed to serve as agent for those owners (and for other airlines or vendors) to file and publish tariffs and related products.

ATPCO Proprietary Standards

Proprietary technical standards established by consensus to provide consistent results for pricing and retailing automation across the travel ecosystem. These include the following documents:

  • Data Dictionary, comprising file layouts, field descriptions, validation edits, and abbreviated descriptions of processing (interface standard)
  • Industry reference codes used in processing (appendices)
  • Full descriptions of data processing (matching and application) to produce a consistent pricing or retailing result (processing standard)
  • Data maintenance (load, store, data management)


Automated Refunds

ATPCO Automated Rules Category 33 that automates the processing of rules and restrictions governing refunds for tickets.

Automated Reissues

ATPCO Automated Rules Category 31 that automates the processing of rules and restrictions governing exchanges for tickets.


An automated process used to price a ticket without human intervention, autopricing is the ability for a GDS to provide eligible fares for a passenger s itinerary by programmatically processing the data coded in the rules and footnotes.


The amount of inventory which is not currently reserved is shown in an availability display.

baggage allowance

A provision that governs the number of pieces or weight of baggage that may be carried free of charge.

baggage charges

A provision that governs the charge for baggage and special items that do not fall within the passenger's baggage allowance.

Banker's Selling Rate

Used during the transfer of funds through banking channels, the rate at which a bank will sell a given amount of foreign currency in exchange for one unit of the national currency of the country in which the exchange transaction takes place.