Some words and letters are such a familiar part of daily life that they almost fade into the background. It's possible to regularly look at these letters while never knowing what they actually stand for. From markings on your electronics, food packaging, and clothes to the words you see on water bottles and inside elevators, here are the meanings behind the mysterious letters you see every day.
Zippers are part of our daily lives, whether on our jeans, coats, or bags and as long as they work, they usually don't receive intense scrutiny. However, a closer look at various zippers will likely reveal that many of them are inscribed with the letters "YKK.”
YKK stands for “Yoshida Kogyo Kabushikikaisha,” which roughly translates to “Yoshida Manufacturing Shareholding Company.” This company, founded in 1934, uses its own brass, polyester, threads, and even zipper machines. By controlling so much of the process, YKK can deliver high-quality zippers. The company also sells these zippers at reasonable prices. The combination has made YKK a go-to in the garment industry — and explains why half of the world’s zippers have YKK zippers.
A.M. and P.M.
Digital clocks, smartwatches, phones — if an item tells time, it will usually also share whether that time is "a.m." or "p.m." Learning the difference between a.m. and p.m. is a part of almost every child's education, but children often don't learn what a.m. and p.m. actually mean, or forget as they get older. A.M. is an abbreviation for the Latin term "ante meridiem," signifying “before noon.” P.M. denotes "post meridiem," Latin for “after noon.”
Also, according to the Physical Measurement Laboratory, which is part of the U.S. Department of Commerce's National Institute of Standards and Technology, "12 a.m. and 12 p.m. are ambiguous and should not be used." They recommend opting for the terms "noon" and "midnight" instead.
You may have spotted a "CE" on eyeglass frames, mobile phones (or their packaging), appliances, electronics, and more. CE stands for the French phrase "Conformité Européenne," which means “European compliance.” The CE designation indicates an item has met the standards to be sold in the European Economic Area. The certification process ensures that products in specific categories adhere to safety, health, and environmental standards. Placing CE on things isn't required outside of Europe, but plenty of manufacturers leave the CE mark on items that are sold both in Europe and elsewhere.
Mobile phones, earbuds, television stations, and other communication devices operate on radio frequencies. In the United States, the Federal Communications Commission checks to make sure these devices can function with no harmful interference. The FCC also ensures a device won't overexpose users to radiofrequency (RF) energy, which is a type of electromagnetic radiation.
After obtaining FCC approval, manufacturers will place an FCC logo on the device and/or its packaging. At first glance, this logo can appear as if it contains just an F and a C next to each other, but a closer look will reveal there's a second C hidden inside the first one.
Maybe you study the insides of elevators to have something to do during your ascent or descent, or perhaps you get nervous and read every bit of elevator signage in search of reassurance it's working properly. If so, you've likely seen "OTIS" emblazoned on an elevator's floor, control panel, or elsewhere. This isn't an acronym or abbreviation — OTIS refers to the Otis Elevator Company.
In the 1830s and '40s, passengers regularly died in elevators when lifting cables broke. Inventor Elisha Graves Otis created an elevator safety brake, and in 1853, showed off his invention at New York City's Crystal Palace Convention by ascending on an open platform, cutting the hoisting rope with an ax, and not falling thanks to the safety brake. Four years later, E.V. Haughwout and Company's department store in Manhattan became the first business to use elevators equipped with this special brake.
After the Otis Elevator Company was founded in 1853 and Otis patented his invention in 1861, Otis elevators helped transform cities. Today, the company continues to make elevators with the name “Otis” displayed inside. The safety mechanisms in present-day elevators even stick to the same basic engineering principles that Otis originally used.
People who don't keep Kosher may have seen the letter U inside a circle on some food items and not have known this indicated the item was processed according to Jewish dietary laws. This letter U is actually inside an O, not a circle; OU stands for “Orthodox Union Kosher.” Some products may be marked with OU-D to indicate that they contain dairy or were made on equipment that handled dairy. OU-P tells people an item is Kosher for Passover.
You can find the letters "PET" on many plastic bottles, including most of the ones that hold beverages. PET is an acronym for the plastic “polyethylene terephthalate,” which is part of the polyester family of polymers.
Above the word "PET" on these bottles, you'll also usually see a 1 in a triangle made up of arrows. This is a recycling code. PET bottles can successfully be recycled, so make sure to do this instead of throwing yours away.
The letters "UL" can be found on many things, including electric plugs, heaters, smoke alarms, and personal flotation devices. UL stands for “Underwriters Laboratories,” a company that's been conducting product safety testing for more than a century. If an item meets UL's safety standards, it earns the right to bear a "UL" mark.
The man who founded what became UL, William Henry Merrill Jr., got the idea to set up an electrical testing laboratory after being dispatched to check fire risks at the Chicago World's Fair in 1893. The Underwriters Electrical Bureau was founded in 1894, and Underwriters Laboratories was incorporated in 1901. UL began offering its label service to certify products it had tested in 1906.
USB is such a familiar term that you may not be aware it's an acronym for "universal serial bus." USB really did live up to the "universal" part of its name. Before USB, serial ports, parallel ports, and more were used to connect external devices like keyboards, mice, and printers. USB made it possible for these different devices to hook up to computers via the same connection.
USB technology was developed by a group of American businesses, notably Intel, and first became available in 1996. When Apple's iMac came out in 1998, it was a USB-only computer. USB is still popular today, as are USB-C ports on phones, tablets, and certain computers.