When booking a holiday it is easy to be confused when it turns out your flight to Vancouver in Canada goes to airport code YVR, or why you will be landing in Malaga, Spain, at an airport with the code AGP. While many main airports have codes which make sense, such as JFK for John F. Kennedy International Airport in New York, of LHR for London Heathrow, others can leave passengers baffled - or in fits of laughter. From unfortunate codes such as OMG and SUX to the funny LOL, there are some seemingly very random three-letter combinations around the world. Scroll down for video . Airline Codes features 438 airports from 94 countries, allowing users to finally understand why certain airlines are tagged as they are . Two aviation fans set out to document the world's airport codes and explain how they were chosen with their website Airport Codes. Listing the origins of 438 airports from 94 countries, they explain the reasons behind the unusual acronyms, such as why many Canadian airport codes begin with the letter Y. COK - Cochine International Airport in India takes its code from the fact it is based in the city of Kochi. DOH - Qatar's glitzy new airport is named for the capital Doha. AGP - Malaga Airport didn't want to take its first three letters from the city name as mal means bad in Spanish. So instead it is AGP, taking 'AG' from the middle of the word and filling with the letter 'P'. SUX - Iowa's Sioux City airport ended up with the unfortunate three letter code SUX and have tried to change it many times. Now it has embraced the name with the tag line 'Fly Sux'. ORD - Chicago O'Hare endedup with the unusua;l flight code which points to its past as Orchard Field. MSY - New Orleans Louis Armstrong's code reflects aviator John Moisant and the nearby Moisant Stock Yards. OMG - Omega Airport in Namibia has the somewhat hilarious code of OMG, which is often used as shorthand for 'oh my God'. LOL - in the spirit of unusual acronyms, the term usually use din text messages to signify 'laugh out loud' is actually Derby Field airport in Nevada, serving Lovelock City (hence the code). When codes were generated in the 1930s, old broadcast radio codes were sometimes used. In Canada, radio stations used Y, and this was reflected in the majority of their airport codes starting with the same letter, as shown with YWG representing Winnipeg. The Australian Business Traveller stated that during the first days of air travel, airports were given a two letter 'weather station' code. As the amount of airports increased worldwide, this two-digit number rose to three so each could be given a unique code. Cities with similar starting names like Dublin and Dubai caused the labelling to deviate from a regular system, with Dubai adopting DXB, when DUB was already assigned to Dublin. The codes are known as IATA location identifiers, and are set by the International Air Transport Association (IATA). The triple characters are displayed on luggage tags at airport check-in desks, to ensure they reach the correct destination. Full lists of the code are published biannually in the IATA Airline Coding Directory. Co-creator Lynn Fisher said she was inspired following hearing a talk about the rationale behind IATA airport codes. 'Ever since I’ve found it interesting and recently did a web search to see if there was a site that compiled all of those stories,' the Arizona-based designer said. 'Nothing came up, so we decided to make one. 'Many airports change names over the years so their airport codes might reflect a previous identity or purpose. 'It’s especially surprising (and interesting) when the code comes from very early or even unofficial designations.' Homer's favourite airport! Airline Codes explains why Hamad International Airport ended up with the DOH code . Many recognise LAX to be the code for Los Angeles Airport, but the extra X on the end has baffled travellers for a while, and can be explained by the transition from two letters to three . The inclusion of an extra letter is the explanation behind the famous LAX code, which was just LA during the 1930s. The airport added the extra X around 1947 to reflect the change in the number of required letters. Several others similarly adopted the X, which can be seen in airport codes such as PDX for Portland, and DXB for Dubai. Codes were sometimes worked out using the city it was located, followed by the name of the airport itself, for example LHR was used for London Heathrow and LGW for London Gatwick. One of the funnier airport codes is Cochin International Airport in Kochi in India, which reverses the first three letters of its place name . Portugal’s second busiest airport, Porto uses the code OPO. It is named after  its alternate English spelling: OPOrto. Confusingly there are exceptions to the rule, with London Stansted airport being given the STN as its code. Perhaps the most entertaining tale on the site is the story of Iowa's Sioux City airport. The unfortunate code for this airport is SUX, which they tried multiple times in vain to change. Once accepting defeat, they used the code to their advantage, using the memorable phrase 'Fly Sux.' Co-creator software engineer Nick Crohn said: 'That’s probably one of the things that’s most enjoyable about the codes. 'They are keys to the airport’s history. 'ORD for Chicago O’Hare points to its past as Orchard Field and MSY for New Orleans Louis Armstrong reflects aviator John Moisant and the nearby Moisant Stock Yards. Lynn admitted the codes that make words like FAT, for Fresno in California, are her favourite. Instead of Malaga Airport using the code MAL, which translates in Spanish as bad, they opted for taking the middle letters from Malaga, and adding a P . Travellers going to Beijing Capital International may be confused to see PEK on their luggage tags. However this is from older English spelling of Beijing, which was PEKing .
The three-letter airport codes are known as IATA location identifiers .
Some follow a pattern like SYD for Sydney and MEL for Melbourne .
Others don't seem to make any sense, like ORD for Chicago .
Airline Codes explains how each airport got its identifying code .