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Why do commercial airflights have those letters and numbers? Here’s why!

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Airport codes, numbers, and technical lingo might seem arcane or even random at first glance, but most have surprisingly logical origins. From international abbreviations to behind-the-scenes terms used by airport staff, there’s a whole coded world buzzing around your flight. Let’s unpack 10 of the most widely used ones.

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IATA airport codes are those three-letter codes you see on tickets and baggage tags, like LAX for Los Angeles or JFK for New York. They're set by the International Air Transport Association (the aforementioned IATA).

These codes often reflect the airport’s name or location, but not always. Some are not as obvious, like ORD for Chicago O’Hare, which comes from its previous name: Orchard Field.

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A relative of the IATA airport codes, UN/LOCODEs are five-character codes used in global trade and transport. They combine a two-letter country code with a three-letter location code, like USLAX for Los Angeles in the U.S.

These codes help standardize locations in shipping, logistics, and customs. You might not see them as often as airport codes, but they’re essential behind the scenes in moving goods worldwide.

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Airport terminal and gate codes help guide you through the airport. A sign like T1-G12 means Terminal 1, Gate 12.

Each airport has its own layout, so the letters and numbers can vary. Some use concourses (like B42), while others just number gates.

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Runway designators are those numbers you see at each end of an airport runway, like 09/27. They’re based on compass directions. For example, 09 means 90°, or east, and 27 means 270°, or west.

If there are parallel runways, you’ll see letters too, like L for left or R for right (e.g., 09L/27R).

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Airline and flight number codes help identify specific flights, like AA100 for American Airlines Flight 100. The first part is the airline’s IATA code, followed by a number assigned to the route.

These codes are used in schedules, boarding passes, and announcements.

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A-CDM codes are used at airports to help controllers and pilots work together smoothly using universal directives. They stand for Airport Collaborative Decision Making.

Some examples of these kinds of codes are TOBT (Target Off-Block Time) and TSAT (Target Start-up Approval Time), which help coordinate when planes should push back or start engines.

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METAR and TAF codes use ICAO airport codes to report weather conditions for pilots and flight crews. For example, EGLL is used in METAR reports for London Heathrow.

These reports include info like wind, visibility, and temperature. METARs show current weather, while TAFs give forecasts.

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Baggage tag numbers and codes are the barcodes that are attached to the luggage when it is checked. They usually include the airport's IATA code, like LAX123456, to help route the bag correctly.

These tags let airports and airlines track bags from drop-off to arrival.

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Flight status codes are seen on airport screens, like ON TIME, DELAYED, or BOARDING, to keep passengers updated. They’re simple but super helpful when you’re rushing to your gate.

Other codes can be spotted, like DEP (Departed), ARR (Arrived), ETA (Estimated Time of Arrival), and GATE CLOSED.

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Flight numbers help identify each flight and usually include four or five digits after the airline code. These numbers aren’t random: they often reveal details like the route, destination, or flight type.

For example, Lufthansa uses 400s for North America and 900s for Asia. Some airlines even assign numbers based on the country of origin.

Knock on wood

You're probably guilty of some: 10 unlucky habits and symbols!

We don't want to alarm you, but there are a huge number of habits, actions, words, objects, and even calendar dates that, according to various traditions, can bring bad luck. You probably already know it's best to be extra cautious with mirrors and avoid walking under a ladder, but other "unlucky" items and actions might surprise you. In fact, chances are you're doing some of them without knowing it! If you want to avoid misfortune, check out these 10 things commonly thought to cause bad luck. Keep your fingers crossed!

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The world of sailing is steeped in customs, beliefs, and superstitions. It's understandable; the sea can be unpredictable, so seeking ways to attract or preserve good fortune makes sense.

One long-standing superstition, which has been around for centuries, claims that changing the name of a boat brings extreme bad luck. According to this tradition, replacing the name is believed to anger the spirits that protect the boat, bringing tragedy to whoever dares to do it.

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While it's always nice to give and receive gifts, there are some restrictions when it comes to luck.

According to many traditions, giving knives as gifts is a bad idea: the object is said to "cut" the bond between the giver and the receiver, distancing them emotionally. However, another custom has emerged as a solution to this belief! If a friend gives you a nice cooking knife, you can simply give them a penny or some other coin in return. The small amount of money turns the gift into a "transaction," effectively warding off bad fortune.

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Many people set a specific day each week to change the sheets. Some prefer to do it on Mondays, to start the week fresh, while others prefer to leave that task for the weekend. Sadly, we have to announce bad news for those in the latter group.

Some cultures around the world consider it bad luck to flip your mattress or change your sheets on weekends, especially on Sundays. This superstition is linked to the meaning of Sunday in many religions, where it's seen as a day of rest and reflection.

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No one can deny the mesmerizing beauty of a rainbow. Something about this phenomenon amazes us and makes us all want to look at it, admire it, and take pictures of it.

But some traditions warn us that pointing at a rainbow can cause bad luck. In fact, according to some beliefs, misfortune could particularly affect the pointing finger, causing it to rot, swell, bend, or even become paralyzed!

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Bad luck doesn't always appear unexpectedly; it sometimes warns you beforehand. But how?

According to this belief, a bad omen can manifest through your body, particularly your nose. While sneezing is a common and everyday act, it is believed to be a sign of misfortune if it happens on the first day of the month or right before starting an important task or process. But don't worry! There's also a solution. Believers claim that you can protect yourself with the famous "bless you."

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We love birthdays! Celebrating another year with the people you love is undoubtedly one of the most beautiful moments. But even in these instants of joy, you have to watch your luck.

Superstition recommends that you should be patient and wait until after midnight to wish a loved one a happy birthday. According to this belief, wishing someone a happy birthday too early can tempt fate. Just in case, let's not take any chances!

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What do you do with your bag or backpack as soon as you enter a place? While most of us hang it up, some might simply place it on the floor. If you're superstitious, it's best to avoid the latter!

It's believed that leaving your backpack, purse, or wallet on the floor invites financial misfortune. Specifically, it's said that this gesture drives away money and abundance, and who would want that, right?

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Unlike your bag, your shoes should always stay on the floor. Or, at least, tucked away in a closet or shoe cabinet. But why?

Shoes are constantly in contact with the ground and the dirt on it. For that reason, it's said that putting shoes on a clean surface—such as a table or countertop—can bring bad luck to the owner of the shoes.

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Often, when we're in a good mood, we go around the house singing, dancing, or whistling. No one can deny that it's great fun, right? However, one of these actions comes with a superstition.

According to many cultures, whistling indoors can have serious consequences. It’s said to attract evil spirits and negative energies into the house. Do you believe it? Just in case, we'll be saving the whistling for open spaces!

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There is a widespread belief among sailors and those who frequent the sea, though it's little known to the general public.

Many ingredients and foods are brought onto boats. However, one fruit is specifically avoided: bananas. It's considered bad luck to bring bananas on board a ship. According to some historians, this belief may have originated because bananas are among the first fruits to spoil, attracting insects and pests.