IT’S part of our everyday clothing but most people never question why shoulder buttons exist.

If you rifle through your wardrobe, you’ll probably find a jacket or coat which has the tiny strap fastened with a button or popper on the shoulder.

And it seems, we’ve finally worked out their use.

One woman took to Twitter to share her discovery with the rest of us after she figured out why they’re attached to our clothing.

Francheska Horsburgh, from Cumbria, wrote: “Taken me 18 years to find out that the weird shoulder buttons on jackets is to hold your bag in place so it doesn’t fall off.”

But it seems she wasn’t the only one in the dark, as her tweet has since gone viral – racking up more than 86,000 likes - after others revelled in her discovery.

And as word spread, it seems the origin of the ‘weird shoulder button’ was also revealed, and it’s military.

Someone posted a screengrab, revealing the feature is a throwback to military uniforms.

It said: “Many military uniform shirts, jackets, tunics or greatcoats feature shoulder straps.

“They were originally designed to keep back packs, ammunition pouches or bayonets from slipping off the shoulder.

“They often display badges of rank, shoulder marks, regimental insignia or epaulettes.”

It seems the information was news to a lot of people, with one person commenting: “That makes so much sense why did we never get that??”

While a third said: “That has blown my mind.”

It seems a lot of people didn’t know what it was for, with another person replying: “Was shocked but makes so much sense I just thought they were there for decoration.”

And it seems people may even use the ‘weird shoulder button’, with another person commenting: “This was a shock to me but what a genius idea.”

Francheska, we salute you.