Learn the lingo

What is a Code Green in a supermarket? Let's decode 10 secret store calls

Ever heard a mysterious "Code Yellow" or "Code 50" over a store loudspeaker and wondered if you should keep shopping or head for the exit? Retailers use coded announcements to communicate quickly without broadcasting every detail to customers. There’s no universal codebook, so the meanings can change from one chain to another, and some operational codes even vary by location. Here are 10 codes you might hear while shopping and what they can mean.

At Walmart, hearing "Code Black" isn't a commentary on the day's sales. Company emergency documentation identifies it as the warning for severe weather, alerting employees that potentially dangerous conditions require attention.

That might mean the sort of storm that makes staying inside safer than heading for the parking lot. Walmart's documented emergency vocabulary also assigns other colors to specific dangers, allowing employees to quickly recognize the nature of a situation quickly without a lengthy announcement.

Orange has a very different meaning in Walmart's emergency system. Company documentation identifies Code Orange as a chemical spill or hazardous materials incident, a situation in which employees may need to secure an area and follow special safety procedures.

That's particularly relevant in a giant retailer selling everything from household cleaners to automotive products. So if you hear the mysterious phrase while debating which detergent to buy, it isn't necessarily time to panic, but employees nearby may suddenly have something more pressing to handle.

At Target, Code Yellow is associated with a missing child. Employee accounts describe it as an announcement that quickly changes everyone's priorities: staff receive information about the child, begin looking around the store, and pay particular attention to exits.

It's a reminder that these seemingly cryptic announcements can have a practical purpose. Instead of publicly announcing sensitive details over the loudspeaker, a short code immediately tells trained employees what kind of response is needed while avoiding unnecessary confusion among shoppers.

This one is considerably easier to guess. Target employees have consistently described Code Red as the store's fire alert. Once it's announced, employees know they're dealing with something very different from an ordinary customer-service request.

Red has a similar association elsewhere, but don't assume retail colors form a universal language. Different companies develop their own procedures and terminology. At Target, Red, Yellow and Green have traditionally distinguished three very different situations: fire, a missing child and a medical incident.

If Target employees suddenly start talking about a Code Green, somebody may need medical help. Long-running employee accounts identify Green with an injury or medical emergency involving a customer or team member.

Employees have recalled Code Greens being called for everything from falls to customers becoming seriously ill. That's also why the deliberately vague wording makes sense: announcing someone's private medical problem to an entire store would hardly help. Two words can instead alert the people who need to respond.

Thankfully, not every mysterious store code signals an emergency. At Lowe's, Code 50 is widely described by employees as a request for loading assistance, usually because a customer has bought something too large or heavy for one person to handle comfortably.

Considering what Lowe's sells, opportunities aren't exactly scarce. Lumber, appliances, bags of concrete, and other bulky purchases eventually have to make the journey from store to vehicle. Code 50 is essentially a discreet way of saying, "We need some extra muscle over here."

Here's another code that's far less alarming than it sounds. Lowe's employees have described Code 75 as a call to collect shopping carts from the parking lot. Available associates may suddenly find themselves heading outside to round up the wandering fleet.

Operational codes can vary between individual locations, so Code 75 isn't necessarily carved in stone at every Lowe's. Still, the mundane meaning makes it particularly fun. That ominous-sounding number coming over the PA may simply mean the cart corral is overflowing.

A Code 22 at IKEA might sound mysterious but, in fact, is used when checkout lines become overwhelmed.

Register-trained workers elsewhere in the store can then be summoned to help handle the rush. Employees have said the call is especially familiar during busy periods such as weekends. In other words, Code 22 is retail shorthand for something shoppers already know perfectly well: that line is getting much too long.

At Home Depot, employee accounts describe Code Orange as an "all hands" request when a department or area needs additional help. Rather than signaling a disaster, it can mean employees are being summoned because customers or work are piling up faster than the available staff can cope.

That's a perfect demonstration of why you shouldn't try decoding store announcements by color alone. Walmart uses Code Orange for a hazardous-material situation, while Home Depot workers have used the same color for additional assistance. Same words, considerably different levels of urgency.

Code 21 may sound like something out of a police drama, but at Walgreens, its reported purpose is much more ordinary. Employees describe it as a call for an eligible coworker when a cashier can't complete an age-restricted transaction because of age requirements.

The exact rules can depend on local law and company procedures, but the basic idea is quite mundane: the person operating the register needs another employee to finish a particular sale. So the next mysterious announcement you hear while shopping might not involve an emergency at all: it could simply be retail's secret language keeping the store moving.

12 times science messed up—and created something incredible

Image: Talha Hassan

Innovation often comes from the most unexpected places. Some of the world’s greatest discoveries and inventions were not the result of a planned experiment but rather accidents, mishaps, or just serendipity. From the creation of irreplaceable household items to revolutionary medical breakthroughs, these chance discoveries changed history. Here are 12 remarkable things invented or discovered purely by accident.

Image: Sandy Millar

In 1928, Alexander Fleming discovered penicillin when he accidentally left a petri dish of Staphylococcus bacteria uncovered. A spore of mold landed on it, killing the surrounding bacteria.

Intrigued, Fleming continued experimenting with the mold, leading to the development of antibiotics that have saved millions of lives and continue to combat infections today.

Image: CDC

In 1895, Wilhelm Röntgen discovered X-rays while experimenting with cathode rays in a dark lab. He noticed that a nearby fluorescent screen began to glow even though it wasn’t directly in the path of the rays.

This accidental finding led to the development of X-ray technology. Röntgen's discovery opened the door for modern diagnostic imaging and is still widely used in hospitals worldwide.

Image: The Oregon State University Collections and Archives

In 1945, engineer Percy Spencer accidentally discovered microwaves' cooking potential when a chocolate bar in his pocket melted while he was working on radar technology.

He then experimented with popcorn kernels, further realizing the power of microwaves for cooking. This serendipitous discovery led to the microwave oven, which became a staple of modern kitchens.

Image: Imthaz Ahamed

Charles Goodyear stumbled upon vulcanized rubber in 1839 when he accidentally dropped a mixture of rubber and sulfur onto a hot stove. The heat caused the rubber to harden and become more durable, which led to the invention of vulcanized rubber.

Vulcanization makes rubber stronger and more elastic, and the process is still used today in products ranging from tires to waterproof clothing.

Image: Ian Talmacs

In 1826, chemist John Walker accidentally invented the first friction match when he scraped a chemical-coated stick on his hearth and saw it ignite. He had been experimenting with creating a new type of explosive but instead stumbled upon a practical way to create fire.

Walker’s matches were the first to be struck on any rough surface, paving the way for modern safety matches.

Image: Hugo Rocha

In 1968, 3M scientist Spencer Silver was trying to create a super-strong adhesive but instead developed a weak one that could easily be removed.

Years later, his colleague Art Fry applied this adhesive to paper and created the now-iconic Post-it Note. Who could have guessed that a bad adhesive could become so popular?

Image: Rob Wicks

In 1938, chemist Roy Plunkett was researching refrigerants when he accidentally discovered Teflon. While he was trying to make a new refrigerant, the gas he was working with turned into a solid, creating a slippery substance that was non-reactive and heat-resistant.

Teflon’s unique properties made it perfect for non-stick cookware. It also found uses in industries ranging from aerospace to electronics, making it a critical material in modern technology.

Image: Carrie Borden

In 1903, French chemist Édouard Bénédictus discovered safety glass by accident. After dropping a glass flask coated with plastic, he noticed that it cracked but didn't shatter.

This led to the invention of laminated safety glass, which is now standard in car windows and other safety applications, and has saved countless lives by preventing dangerous shards from flying during an impact.

Image: Giorgio Trovato

In 1942, Dr. Harry Coover accidentally invented Super Glue while attempting to create a clear plastic for gun sights. He discovered that the substance he had created was incredibly sticky, but too sticky for its intended purpose. The compound, called cyanoacrylate, was shelved for being too impractical at the time.

However, when the remarkable adhesive properties of the substance were later re-examined, it was commercialized under the now-ubiquitous name "Super Glue" and quickly became a household staple for all kinds of quick fixes.

Image: Call Me Fred

In 1907, Leo Baekeland discovered the first synthetic plastic while trying to create a synthetic substitute for natural rubber. His accidental combination of phenol and formaldehyde led to a substance that was heat-resistant and very durable.

In fact, Bakelite marked the beginning of the plastic age. It revolutionized manufacturing worldwide, allowing the creation of everything from household items to electrical components.

Image: jesse orrico

In 1956, engineer Wilson Greatbatch accidentally invented the pacemaker while attempting to build a heart rhythm recording device. By installing the wrong resistor, he unknowingly created a device capable of regulating heartbeats.

Who would have thought that a simple circuit mix-up would lead to such a revolutionary medical breakthrough?

Image: Alexander Grey

In 1879, chemist Constantin Fahlberg accidentally discovered saccharin while working with coal tar derivatives. He forgot to wash his hands and later noticed a sweet taste on his fingers.

Curious, he traced the unusual taste back to his experiment and recognized the potential of the new substance. Saccharin went on to become the first artificial sweetener, still widely used today in diet sodas and sugar substitutes.