1. Numbers on Produce Stickers

On fruits and vegetables, these numbers do not just tell us where these products come from, but they have another purpose as well. For example, the way a specific fruit or vegetable is grown.
If you find a 5-digit number starting with 9 – this product is grown organically. A 4-digit code starting with 3 or 4 – this product is grown conventionally. A 5-digit code starting with 8 – this product has been genetically modified.
2. Brushes on Escalators

Some confident and bold people may use these brushes to clean their shoes on the way. However, their original purpose is to remind people that they are too close to the edge of the escalator and need to stay away from this area. Otherwise, clothing or shoes could get stuck, posing a danger.
3. Bitter Tasting Nintendo Game Cases

Nintendo games are extremely popular with both adults and children. However, children sometimes try to taste or even eat them. To prevent this, Nintendo decided to add some flavors to their game cases. They are intentionally coated with harmless chemicals to create an unpleasant bitter taste in the mouth, making children, or anyone else, never want to try tasting them again.
4. Google Assistant Can Be Controlled with Magic in Harry Potter

On Android phones, if you open Google Assistant and say the spell “Lumos Maxima,” the phone will automatically turn on the flashlight. Saying “Nox” will turn it off. Saying “Silencio” will silence all notifications and alerts on your phone.
5. Dents on Golf Balls

Initially, golf balls were smooth and round, but it turns out that the dents help them fly farther. A smooth golf ball will travel only about half the distance compared to a dimpled golf ball. This, along with many other factors, can determine the outcome of the entire game.
6. Circles at the Bottom of Chip Bags

Some people speculate that their colors may relate to how the product is made. Green – organic, black – genetically modified… In reality, these mysterious circles are called color blocks of the printer. Manufacturers need to check whether everything has been printed correctly and indicate where to cut the product packaging.
7. The Ring on 3.5mm Jacks

Sometimes we may notice that the end of the 3.5mm jack can have one, two, or three metal rings. Their main purpose is to separate the electrical pulses received from devices to transmit information. For instance, a single ring in a headphone jack means it can only provide a mono audio signal, meaning both sides of the earbuds receive the same information accurately. Two rings can separate two signals and transmit stereo sound, making your left and right earbuds produce slightly different sounds. Three rings are typically found in devices with microphone support.
8. The Open Cap Symbol on Cosmetics

On most makeup packaging, we can find labels like 12M or 24M. These are called symbols indicating the lifespan after opening. Their main purpose is to indicate the expiration date, with the accompanying number representing the number of months.
9. Shake to Undo Actions on iPhone

While using the Notes app on the iPhone, you might accidentally delete an important note or create a typo in the text. There is no undo button, so it seems a bit annoying to try to recover everything. A quick and easy way to undo is to shake your phone. After a moment, you will receive a pop-up notification guiding you on how to undo previous actions.
If this feature doesn’t work, go to “Settings,” find “Accessibility,” and then the “Shake to Undo” option.
10. The Benefits of Wooden Hangers

Besides being more durable than plastic and suitable for heavy coats, wooden hangers have many more benefits. Hangers made from cedar wood can help repel moths in your wardrobe. Additionally, the wood itself can help absorb unnecessary moisture and eliminate unpleasant odors.
Source: Brightside