Although bright yellow signs with the letter 'H' on them are common attached to lampposts across the United Kingdom, how many of us actually know what it stands for and what their use is?
People have recently been stunned to find out what the purpose of the signs actually are, after South Yorkshire Fire and Rescue Service took to social media to explain how the markers are used to save lives.
The Mirror reports that the signs play a significant role even though many UK residents and visitors alike walk past them each and every day without giving them a second thought.
Read more: People are only just working out what their washing machine's three trays are actually used for
And Birmingham Live reports that the Yorkshire-based fire service took to TikTok to explain, writing: "POV: You’ve walked past these small yellow signs your whole life. But it was today you realised, finally, after all these years, they are there to tell firefighters where the hydrants are."
The photograph displayed in the short video tells firefighters that there's a 100mm water main 10 metres away - leaving people completely flabbergasted by the explanation. "I never knew. Everyday is a school day thank you," one TikTok user wrote, while another, added: "Well I learnt something new today thank you!"
A third added: "I’ve never even seen one of these signs never mind know what it means," while a fourth commented: "Good to know. Thank you for sharing."
"I used to think it was H for helicopter landing," one user admitted - with others in agreement. "I thought it was a helicopter landing pad," a second said, with a third echoing: "thought it was H for helicopters".
Last week social media users were gobsmacked to learn the origin of the term blockbuster. A TikTok star shared a video that detailed the word's origin.
The word is so synonymous that the popular but now defunct video rental store named itself after the term - but many don't know the word's historic meaning. TikTok user Alice James, 30, shared where it came from - leaving people in shock as many admitted that they had no idea where it originated.
Taking to TikTok, where she uploads as @alicekjames, Alice said: "Are you ready to have your mind absolutely blown? I learnt what the term 'blockbuster' meant the other day and I haven't stopped thinking about it. It comes from the fact that in the olden days if a movie was a blockbuster it meant the line went around the block to buy tickets."
Alice's video soon went viral and had over 150,000 views alongside countless comments.
One viewer admitted: "I didn't know this either and I'm 59."
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