Travel Glossary: Acronyms and Terms Explained

Travel Industry Basics

I am interested in what a travel business can actually do for the person buying the trip. Can it issue the ticket itself? Does it have rooms when another seller has sold out? Can the person answering the telephone change the booking, or must they ask someone else?

The industry’s language starts to become useful when it answers those questions. An abbreviation can reveal who controls the reservation, what you have paid for, or where a request still needs a decision. I have chosen the terms below for that practical value, with links to fuller explanations where the machinery deserves more space.

People and businesses

Pax: People or passengers. In activity quotations, “1/2 pax” counts a child as half a unit: two adults and a child can be counted as 2½ pax for the commercial calculation. Three people still attend and need to be accommodated. This is a commercial counting convention; it does not by itself establish every supplier’s child age bands or charges.
OTA—online travel agency: An agency selling travel online, such as a hotel stay or flight supplied by another business. It combines choice, price and booking support. The hotel may change your room while a refund still has to go through the agency that sold it. How hotel booking works follows those separate responsibilities.
Tour operator; TO; TTOO: A business assembling travel arrangements, often combining flights, hotels and transfers into a holiday. It can negotiate accommodation and commit to transport before you decide to travel; that buying position helps explain why a package can cost less than the same parts bought separately. It also gives you an organiser to contact about the combined arrangements. TTOO or TT.OO. is common shorthand for tour operators in Spanish trade material. Identify the organiser as well as the agency selling its holiday.
DMC—destination management company: A destination management company supplies the local arrangements: drivers, guides, excursions and the people who make an itinerary work. It may deliver a holiday sold by a business in your home country. The overseas seller handles your contract; the DMC may be the company able to send a replacement vehicle when the transfer fails. Its local assistance number is worth keeping.
DMO—destination management or marketing organisation: A destination management or marketing organisation works on a place’s development, promotion or visitor information. A tourism board is a familiar example. It can help with official events, transport and the wider region. Its recommendations also serve its purpose of promoting that destination; they are not necessarily independent editorial selections.
Bedbank; hotel wholesaler: A hotel wholesaler supplying rooms to other travel sellers. Your booking website may buy through one, so the hotel’s record can show a supplier name you do not recognise. The retailer may then need the wholesaler to arrange a change with the property. If reception cannot find you, your seller should trace that chain and supply the hotel’s reference.
Airline consolidator: A business supplying fares or issuing airline tickets for other travel sellers. An agency without its own ticketing accreditation may use one. This is a normal arrangement, but a change or refund can require another business’s involvement. For a complex itinerary, the useful question is how quickly your seller can reach the ticket issuer when you need help.
Ground handler: A company carrying out airport work for an airline, including check-in, baggage handling or preparing the aircraft. Staff at the counter may work for the handler rather than the airline. They can accept your bag yet lack authority to refund or reissue a ticket. For that action, ask for the airline desk or ticketing contact they can refer you to.

Hotel rooms and contracts

Allotment: A contracted allowance letting an operator confirm rooms without asking the hotel about each booking. With deferred reporting, the guest can be booked before the hotel receives the individual reservation. That explains why one agency can confirm immediately while another needs an answer. The allotment guide follows that relationship.
Release period; cutoff: The interval before arrival by which the operator reports sales and returns unused allotment in the arrangement described here. A seven-day release gives more late-selling freedom than fourteen days, but leaves the hotel less time with a complete picture. This supplier deadline is separate from the traveller’s cancellation conditions.
Recap: A current sales report the hotel requests from an operator: which rooms have already been sold, for which dates. Those bookings may exist before the hotel receives their individual details. A recap updates the hotel’s information without automatically ending the operator’s authority to sell. It helps the hotel decide what to leave open or restrict. The guest sees the consequence in availability and confirmation speed.
Release reduction: A contract amendment reducing the operator’s late-selling flexibility for specified arrival dates. Moving release from seven to fourteen days means sales must be reported and unused rooms returned earlier. The number increases; the operator’s freedom decreases. The hotel gets more time to act on a complete picture. An agent may consequently need to request a room individually sooner than it did under the original agreement.
Zero days release: The reporting deadline falls on the arrival day itself, at the agreed cutoff. Zero does not mean there is no deadline: it leaves no advance-day margin for the hotel to absorb a surprise in the operator’s sales. It describes timing; commitment separately determines the financial risk. The allotment guide explains the controls.
Stop-sale; stop-sell: A hotel’s instruction to an operator to report sales already made and stop further confirmations from its allotment. New business can still go on request. The hotel can target particular partners and dates; it need not close every channel. A stop-sale does not itself cancel bookings the operator was already authorised to confirm.
Commitment; guaranteed allocation: An agreed financial obligation for capacity, including rooms or seats the seller may never resell. A discounted booking can be better than an empty place it must pay for anyway, which explains some late package offers. This is the business’s obligation to its supplier; your own payment and cancellation conditions remain those in your offer.
Free sale; free sell: Permission for a partner to sell under agreed terms without asking about every booking. When the hotel has ample capacity, free sale makes it easier for the operator to complete a booking and encourages staff to offer that property. The rate need not fall: convenience for the sales team is an incentive in its own right.
On request: The operator must ask the hotel to accept this booking before confirming it to you. That can remain possible after a stop-sale ends automatic allotment sales: the hotel is controlling each new booking, not necessarily declaring itself full. Until the answer arrives, it is a request rather than the confirmed stay on which to base other purchases.
Pooled inventory: Several sales channels draw from one stock of rooms. Five rooms shown on three websites may be the same five, with each sale reducing the shared balance. Shopping across websites can reveal different prices without revealing more physical rooms. The connected-booking explanation shows how the balance is updated.
Overbooking; overselling: More reservations have been accepted than the available capacity. In the hotel operator model explained here, overlapping allowances and delayed sales reports can produce that shortage. My hotel guide covers reducing the risk and negotiating at reception. Airlines can deliberately oversell against forecasts of passengers who will not travel; a smaller replacement aircraft can also leave too few seats. Those different causes, boarding priorities and volunteer offers are explained in flight overbooking.
Inventory drop: A loss of rooms previously available to sell, for example when damage makes a suite unusable. A rare category may have no equivalent left within the property, even though ordinary rooms remain. That differs from selling too much capacity. A hotel choosing to give your room to an owner or preferred guest is a separate management decision, not an unavoidable repair. In either case, establish the reason and seek a replacement that preserves what you booked.
Walk a guest: Relocate a guest because the booked hotel cannot accommodate them. A suitable replacement concerns the room category, location, inclusions and dates, as well as the move itself. My hotel-overbooking guide explains how I would negotiate the replacement and transport at reception.
No-show: Failing to arrive for a booking without cancelling as required. The consequence can extend beyond losing that night or flight. On some airline tickets, missing one flight can lead to the remaining sectors being cancelled. A hotel also needs to know if a late arrival will become an arrival the following morning. Tell the seller or supplier what you intend to use and have the remaining arrangements confirmed; silence leaves the system to apply the booking’s rules.
Room type; room category: The accommodation category you buy, usually shared by several rooms rather than identifying one room number. It can establish the beds, space and view being sold. A general hotel gallery may show several categories. If the view is why you chose the stay, it belongs in the booked description; a request for a better view is not the same purchase.
Rate plan: The commercial conditions attached to a room: meals, payment timing, cancellation rules and other inclusions. The physical accommodation may be identical under two different plans. I might pay more for the same bed because the flexible rate allows uncertain dates to change. Comparing the conditions explains what the higher price is buying.

Meals and hotel language

F&B; AyB: Food and beverage: the hotel operation responsible for restaurants, bars and related dining services. In Spanish, alimentos y bebidas becomes AyB or A&B. This is the department for a dining arrangement or recurring restaurant problem. “FB” in a meal-plan column means something else: full board.
Board basis: The meals included with the stay: RO is room only; BB or B&B includes breakfast; HB is half board, usually breakfast and one main meal; FB is full board, usually breakfast, lunch and dinner. The choice is partly about how you want to spend your days. I would be less interested in prepaid lunches if I planned to be out exploring. Establish which meal half board includes, where you may eat and whether drinks are extra; the initials alone do not settle the bill.
AI—all-inclusive: A defined package of meals, drinks and sometimes activities included with the stay. Its value depends on what you will actually use. Included cocktails are no great saving to someone who wants good wine with dinner, and a resort’s restaurant count says little if most require supplements. I look at the included venues, drinks, booking requirements and service hours. The package can make a holiday pleasantly simple, but compare the actual inclusions rather than buying the reassuring phrase.
Complimentary: Provided without a separate charge, such as breakfast or an airport transfer. It is worth asking what exactly is included: a shared transfer and a private car do different jobs, even when both are complimentary. The word describes the charge, not the quality or exclusivity of the service. “Complementary”, with an e, simply means that things go well together; it does not promise that either is free.
PPPN; PPPD: Per person per night; PPPD means per person per day. A €100 nightly price per person becomes €200 for two before separate charges. Compare the total for your actual party and stay, with the meals and fees included, rather than putting a per-person figure beside a per-room one.
Single supplement: An extra charge when one person occupies accommodation priced on the assumption that two will share it. Much of the room’s cost remains even though only one guest uses it. On a tour or cruise, compare the final solo price rather than the supplement alone: a low base fare with a supplement can still beat a higher “no supplement” offer. Also establish what room or cabin you receive; removing the supplement does not necessarily preserve the same accommodation.

Systems and pricing

PMS—property management system: The property management system holds the hotel’s operational records: reservations, arrivals, room status and guest accounts. It does not necessarily show every room already sold by an operator under a deferred-reporting allotment. If the hotel cannot find a booking, the seller needs to trace its reference and reporting status. An absent entry can be a handover still to complete; it is not, by itself, proof that the traveller’s confirmation is false.
CRS—central or computer reservation system: A central reservation system distributes rooms, rates and bookings, often for a hotel group. In aviation, CRS commonly expands to computer reservation system. The distinction matters when the central reservations office and the property appear to know different things. A booking may have been made centrally, while a local arrangement still needs the hotel’s acceptance. For an essential room feature or arrival arrangement, I want the property to acknowledge it, not just a central agent to add a note.
Channel manager: Software passing rates, availability and reservations between a hotel and connected sellers. Selling a room in one place reduces what can be sold elsewhere. Delays or incorrect room-category settings can interrupt that exchange. If the hotel blames the channel manager, the practical issue is whether it has your reservation and can supply the booked room.
Booking engine: The part of a website where you choose dates and an offer and complete the reservation. A hotel’s own site can use a specialist company’s booking engine, so a new web address during checkout does not necessarily mean you have left a direct booking. The named supplier, payment recipient and booking terms establish the transaction.
API—application programming interface: An application programming interface lets one system request information or actions from another: retrieve a fare, send a reservation or update availability. For a traveller, the important point is that a working search connection need not support every later change. A website may sell an offer but need staff to handle its refund or amendment. I would assess that service before a complicated trip. In border paperwork, API means something else: Advance Passenger Information.
GDS—global distribution system: A global distribution system connecting sellers to airline, hotel and other travel products. It lets an agent compare and manage bookings, but access is separate from authority to issue an airline’s tickets; the agent may use a consolidator. It also does not guarantee every fare is visible. See how GDS and NDC connections work.
NDC—New Distribution Capability: An IATA standard for exchanging airline offers and orders, including the flight and extras such as baggage or seats. It can carry offers unavailable through a traditional fare feed. NDC can run through a GDS as well as other connections. The distribution guide explains why selling and changing a booking can involve different capabilities.
Dynamic pricing: Prices change as the seller reassesses demand and capacity. A place held for a higher-paying customer can become cheaper if that prospect fades. This differs from comparing two products with different baggage, meals or cancellation terms. The airline pricing guide follows how a changing forecast becomes the fare on your screen.
Revenue management; yield management: Deciding what to charge and which bookings to accept from limited capacity. Yield management is closely related language; revenue management can consider a wider range of income. A seller may preserve a place for a different customer or itinerary. The airline example explains why filling every seat is not the same as earning the most revenue.
Displacement: The sale a business gives up by accepting another booking. One Saturday night can prevent a hotel selling the room for a valuable three-night weekend. That explains why a one-night search can fail while a longer stay is available. For flexible plans, compare complete stays you would actually want; an unwanted extra night is still a cost.
BAR—best available rate: A hotel’s named public rate structure, often changing by date and conditions. “Best” is part of the label, not proof that every seller has been compared. A member, package or restricted offer may cost less. Compare the same room, meals and cancellation conditions before treating the rates as interchangeable.
ADR—average daily rate: Average daily rate: room revenue divided by rooms sold. It tells a hotel what it earned on the rooms it occupied, but ignores the rooms left empty. If two occupied rooms sell for €100 and €300, their ADR is €200; neither guest necessarily bought a €200 room. For a traveller, this is a useful antidote to treating an “average room rate” as the price you ought to receive for your own dates and category.
RevPAR—revenue per available room: Revenue per available room divides room revenue across the hotel’s available capacity, including empty rooms. Imagine a ten-room hotel selling five rooms at €200: room revenue is €1,000 and RevPAR is €100. Selling all ten at €80 would fill the property but produce only €800. That helps explain why a hotel may resist discounting simply to look busy. These are illustrative room-revenue figures, not profit calculations; costs still have to be paid.

Flights and airports

IATA—International Air Transport Association: The airline trade association behind agency accreditation and the Billing and Settlement Plan, which help organise ticket issuance and settlement. Accreditation can require financial security such as a bank guarantee, depending on the programme, market and risk assessment. An agency may issue tickets with an airline’s authority or work through another accredited business; that affects the route a change or refund takes. Accreditation is separate from GDS access, and the security is not the traveller’s personal insurance.
BSP—Billing and Settlement Plan: IATA’s system for reporting sales and settling money between participating airlines and accredited agents. It avoids a separate settlement process with every airline. Your payment, ticket issuance and the agent’s later settlement are distinct events: after paying, the document you need is the ticketing confirmation, not access to the agency’s accounts.
ICAO—International Civil Aviation Organization: The United Nations specialised agency through which states work on international civil-aviation standards. It does not accredit your travel agency. Its four-letter airport indicators and three-letter airline designators differ from the commercial IATA codes passengers usually see. That explains why an aviation app and your ticket can use different codes for the same airport.
PNR—passenger name record: The passenger name record holds reservation details for a person or party. People also use “PNR” for the code retrieving it. A record can exist before ticket issuance, so receiving a booking reference does not always mean ticketing is finished. The booking-record guide explains what each document establishes.
Record locator; booking reference: The code that finds your reservation in a particular system. Your agency and the participating airlines can use different locators for the same journey. If the operator’s website rejects a reference, ask for its own code before assuming the booking is missing. This is especially useful for seat selection and online check-in on a codeshare. Keep the reference private: combined with a surname, it can give access to booking details in some systems.
E-ticket; ETKT: An issued electronic ticket, commonly identified by a thirteen-digit number. It can be traced separately from a payment receipt or an itinerary awaiting issuance. Some airlines use ticketless processes instead. The ticketing guide distinguishes an issued ticket, a held reservation and the booking reference used to retrieve them.
Booking class; RBD: A reservation booking designator, often a letter, identifying fare inventory within a cabin. Neighbouring economy passengers may have different booking classes, fare conditions and mileage earnings. A cheap class can close while seats remain in the cabin. The letter helps identify the fare being sold; it does not describe a better seat. See airline pricing.
Codeshare: One airline markets a flight under its own number while a partner operates the aircraft. Several numbers on a departures board can refer to the same physical departure. Read “operated by” before choosing the flight: it helps identify the cabin product and the airport arrangements you will actually use. Then read the allowance on your ticket rather than infer the baggage rules from a logo. The codeshare guide separates those responsibilities.
Marketing carrier: The airline whose code is used to sell a flight. It may offer different fares or loyalty eligibility from another airline marketing the same departure. Its code does not mean its own aircraft operates the service. The operating carrier and ticket issuer have separate roles, explained in the codeshare guide.
Operating carrier: The airline actually operating the flight. Its aircraft and onboard service are central to the experience you are choosing, and its instructions are the starting point for check-in and cabin-baggage requirements. For a journey sold by a partner, obtain the operator’s reference if you need to manage seats or check in with it. I would read this line before buying an attractive business-class fare: the name in large type can tell you less about the cabin than the small print below it.
Interline: An arrangement for airlines to work together on matters such as ticketing and baggage across a journey. It can simplify a connection, but it does not automatically turn separately bought tickets into one protected trip. The ticketing arrangement and the route on which your bag is checked remain the relevant details.
SSR—special service request: A special service request in an airline booking, such as assistance or a particular meal. Recording it and having the operating airline accept it are different steps. An essential arrangement may need to cover each flight. “Has the airline accepted the request for every flight?” is more precise than asking whether a note is in the system.
OSI—other service information: Other service information: a message passed to an airline through the reservation. It provides context but is not interchangeable with an accepted special service request. This matters when an agent has recorded a need but the airline still has to agree to provide the service.
API; APIS—Advance Passenger Information; Advance Passenger Information System: Advance Passenger Information is the identity and travel-document data supplied for border processes; APIS refers to an Advance Passenger Information System. This is separate from the name and ticket in your reservation. Correcting passport information in an online form does not necessarily correct a misspelt ticket name. If the booking itself is wrong, contact the seller about that record rather than assume a later passport-data entry repairs it.
DCS—departure control system: The departure control system supports airport processes such as check-in and boarding. It is distinct from creating a reservation, although the systems are connected. If a valid-looking itinerary cannot be checked in, identifying whether the problem concerns the reservation, ticket or airport acceptance helps staff find the part that needs fixing.
MCT—minimum connection time: Minimum connection time: the published interval used for particular combinations of connecting flights at an airport. It helps determine which connections can be offered, but it is a minimum working allowance, not a measure of comfort. I would want more margin with a child, limited mobility or a particularly important onward journey. For separately bought flights, do not borrow a through-connection minimum as your planning allowance: collecting bags and checking in again can create a different journey through the airport.
IROPS; IRROPS: Irregular operations: disruption such as delays and cancellations. IROPS and IRROPS are both used. It distinguishes a change imposed by the airline from a change you choose to buy. Before paying to move yourself off a disrupted flight, ask what alternative the airline offers because of the disruption.
Denied boarding; bumping: A passenger cannot travel on the booked flight. When capacity is short, an airline may first offer benefits to volunteers who agree to give up their places. That negotiated bargain differs from being refused boarding against your will, which can trigger statutory compensation and other assistance. The reason and route matter. Before accepting, establish whether the airline is asking you to volunteer or telling you that you cannot fly. My flight overbooking guide explains what I would settle at the gate.
Standby: Waiting for a place on a flight without a confirmed place on that departure. If an airline offers standby as the alternative when seeking volunteers, the arrival time remains uncertain. Ask which flight it can confirm before deciding what your flexibility is worth. Standby is different from holding a confirmed ticket whose seat number will be assigned at check-in or the gate.
Downgrade: Travelling in a lower cabin than the one bought, for example economy instead of business. A replacement aircraft may have enough seats overall but fewer in your cabin. Establish the available alternative flights before deciding whether to accept the lower cabin, then discuss the applicable reimbursement. The rules for a downgrade differ from those for being refused the flight altogether; a seat-number change within the same cabin is not automatically a cabin downgrade.

Cruises, rail and the journey ashore

GTY—guarantee cabin or stateroom: A guarantee booking leaves the exact cruise-cabin assignment to the line within the agreed category and terms. I would assess it on the minimum promised, not the possibility of an upgrade. Essential requirements such as accessibility or neighbouring cabins need a specific arrangement. The guarantee-cabin guide explains the exchange of choice for price.
OBC—onboard credit: Onboard credit against eligible shipboard spending. It is worth what it replaces from your planned purchases, not automatically its face value. Restrictions, refundability and unused balances matter: a large credit that cannot buy what you want can be less useful than a smaller fare or a benefit you would otherwise pay for.
Shoreside: The land-based side of a cruise operation, as distinct from the staff and services aboard the ship. If a matter has been referred to shoreside, the decision may be with an office rather than the person at Guest Services. Ask who is handling it, how you will receive the answer and what reference to keep after disembarkation. It helps turn “we have passed it on” into a follow-up you can actually make.
Tender: A smaller boat taking passengers between an anchored ship and shore. A tender call adds a transfer and sometimes a queue before the land excursion begins; the ship’s arrival time is not necessarily the time you can meet a guide ashore. It also changes the access question. An accessible cabin does not establish that every tender can take your wheelchair or mobility equipment. Confirm the arrangement for the relevant port when going ashore is an important part of choosing the cruise.
Berth: A sleeping place on a train or ship; in a port, a place where a vessel lies alongside. Two sleeping berths need not mean a private compartment. The number of other occupants and whether the places are upper or lower can materially change the night. See the rail-reservation guide.
Seat reservation: An allocated place on a specified service. On a railway it can be separate from the ticket giving permission to travel. A flexible ticket may let you take another departure while the reserved seat remains on the original train. Keep both entitlements in view, especially for a long journey or when sitting together matters. The rail-booking guide explains when the reservation is optional, compulsory or included.
Rail pass: A travel entitlement covering specified networks and travel days. Compulsory reservations, supplements and limited pass-holder availability can restrict its flexibility. For a trip built around one essential train, check that reservation before buying the pass. The rail guide explains how a valid pass and an unavailable seat can coexist.
Through-ticket: A ticketing arrangement covering successive services as a journey. It matters most when an earlier service is late and the connection fails: the ticket arrangement and applicable rules help determine who must assist and what alternatives you can use. Several flights or trains in one checkout are not enough to establish that arrangement. Ask the seller to identify whether it is a through-ticket or separate tickets before treating a short connection as a reasonable risk.
Coach: A railway carriage, a road vehicle used for tours or longer journeys, or—in some airline usage—economy class. The context changes the meaning. On a rail reservation, “coach 4” tells you which carriage contains your seat. In a holiday’s transfer description, “by coach” describes the vehicle, not a private transfer; establish whether the service is shared and makes other hotel stops. That can change how the first and last hours of your holiday feel.

The question behind the abbreviation

I have little interest in jargon as a display of expertise. I want it to make the arrangement clearer. When an answer is full of initials, bring the conversation back to your trip: who is confirming this, what is included, and who can act if it needs changing? The useful professional is the one who can answer.

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Travel acronyms and terms