WHEN washing clothes, the symbols on labels can be invaluable to make sure you don't shrink your favourite items.
The machine wash icon telling you to pick a 30C cold wash is pretty self-explanatory, but some of the other images can be more obscure.
And some people have only just realised that the dots inside the washing, drying, and ironing symbols are significant - indicating the temperature to use.
When it comes to tumble-drying and ironing, you'll see one dot to indicate "cold," two for "medium," and three for "hot."
Posting on TikTok, one dad admitted: "I have only just discovered that the iron symbol on every label has dots so that you can put your iron [to] the exact setting for a perfect smooth ironing experience.
"Did everyone else know this or am I late to the party?"
His clip, captioned "something we should all probably know", has already racked up more than 500,000 views.
And many social media users were also unaware of the dot hack.
One gushed: "This has just saved my life."
A second wrote: "I learn more on TikTok than I learnt at school, I swear."
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Meanwhile, another said: "Omg I never knew this. Amazing."
But not everyone is impressed by the 'discovery'.
One blasted: "How old are you? I am 26 and I knew this since I was 13 and started ironing my own clothes."
Another agreed, writing: "My mam told me this when I was a kid. Don't understand why life skills aren't passed on."
And a third said: "Omg I've known this since a little kid."
It's not just dots that form part of the secret code.
Pay close attention to the two different X symbol placements on an iron.
An X over the bottom of the iron means "do not iron with steam," while an X through the whole thing means no ironing, period.