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Glossary for the airline industry

Definitions and explanations of common terms in the airline industry

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.

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.

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.

base amount

1. An amount representing the highest selling local fare used in certain markets under the IATA Multi-lateral Proration Agreement. Base amounts are published in the IATA Prorate Manual--Passenger (PMP).

2. A base fare used in Category 25 as a calculation tool to produce Net or Selling amounts.

base fare

1. The fare amount excluding taxes and other charges. However, charges resulting from Stopovers (Category 8), Transfers (Category 9), and/or Surcharges (Category 12) processing are included in the base fare. This amount appears in the "fare" portion of the Fare Box on the ticket.

2. A fare or fares used as a basis for calculating other fare amounts to create a resulting fare in Category 25 or in Categories 19-22. This may also be the fare amount filed in the Fare Record


A unit of work containing a group of transactions that are entered and released to the file, used for describing a set of instructions that are being implemented. Every batch is identified by a two-character alphanumeric code (based on batch ID of user) plus a control number assigned by the system. The batch header specifies the proposal number, tariff, carrier, effective date of transactions, and the batch status (public, private, or incomplete). See also batch processing.

batch number

A number preceded by the alphanumeric ID code of the compiler or airline and assigned sequentially by the computer. This number goes on a batch sheet or is used online to be associated with a group of updates or transactions.

bid pricing

A type of continuous pricing where airlines link their revenue management systems directly to price determination.

bilateral agreements

An agreement between two nations concerning rate or fare levels. This, in some instances, supersedes normal filing requirements for the DOT. Also refers to special prorate agreements between two carriers.