There are many signs and symbols that are easy to work out, from the well known flammable symbol to road signs that warn of speed bumps. But there are some signs that many might not recognise right away.
One that people may walk by on a regular basis - but pay no attention to - is an 'H' that you will find on some lampposts. Recently, curious social media users began to theorise what this might mean, as many didn't know what the single letter sign stood for.
And soon after, a UK Fire and Rescue team revealed what the letter signified. According to the experts, the signs are there specifically for firefighters, writes the Mirror.
In a video posted to the @southyorkshirefire TikTok account, they wrote: "POV: You've walked past these small yellow signs your whole life. But it was today that you realised, finally, after all these years, they are there to tell firefighters where the hydrants are."
The signs show firefighters the locations of water supplies when they need to extinguish a fire. The sign can be very helpful if the hydrant cover is obscured in some way.
As well as lampposts, the signs can also be attached to walls and small concrete slabs which protrude from the ground.
The Fire and Rescue Service also shared what the numbers on the yellow signs mean. They said that the top number denotes the width of the hydrant in millimetres, and the bottom number shows the distance of the cover from the sign in metres
With over 1million views, social media users were clearly impressed with the revelation. Commenters on the video said they were only just discovering the meaning behind the signs, with some joking they thought it stood for 'helicopter pad'.
"I never knew. Every day is a school day thank you," one person wrote in the comments. Another added: "Well, I learnt something new today. Thank you!"
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