Two & Three Letter Codes
When using OAG Travel Planner Pro to select flights, you will first need to select the route and date of travel. The system will offer you a choice of flights:
As an example - here we will look for a flight from Rome, Italy to Istanbul, Turkey at any time on 20th April.
There are two flights. Both flights are direct (ie there are no connections). If we want to find out more details about the flight, we will click on the relevant flight number: AZ074.
If you are working in OAG Travel Planner Pro, click on Operator Info, your click will bring you the information below:
This tells us that AZ is the two letter code for Alitalia. We can also see which airport and terminal to check in at Rome. You can find out more about the airports by clicking on their codes. For example, clicking on Airport Diagram will bring up a useful map of Fiumicino airport in Rome.
Here is another example as we look for flights from Amsterdam, Netherlands to Chicago, USA on the 20th of April.
We see 6 options displayed. You'll notice that the first lines shows a pair of planes and double flight number. This indicates connecting flights, so the the traveler will have to change flights.
We are interested in the second line: CO6041. It has a single plane, one flight number and if you check the Duration column, you'll see that its faster than the flight above. (Duration means actual length of time it takes to travel from departure airport to arrival airport).
Clicking on the flight number CO6041 takes you to this screen:
These details show that CO is the two letter code for Continental Airlines, operated by United Airlines. You can see that you could click on Airport Diagram to find an airport map.
Other Two and Three Letter Codes
A word of warning. You may come across other codes that look like two letter airline and three letter airport/city codes in travel guides, timetables and websites. Don't confuse them, these other codes are:
* Two letter codes for States and Provinces. For example if you see Atlanta, GA, the two letter code relates to the US state of Georgia, rather than Garuda airlines.
* Three letter codes for Currencies. For example, MAD 30,000 refers to the currency Moroccan Dirham, rather than the city of Madrid.



