With the Queen's Jubilee and the London Olympics this year, national pride is at an all time high, with Union Flags beginning to appear in shop windows and houses.
However, as Chorleywood Business Association found out this week, due to a subtle difference in the thickness of the red and white stripes, there is a correct and incorrect way to fly the flag.
To celebrate a French Market coming to the town this weekend, Main and New Parade has become a sea of Tricolores and Union Flags.
Eagle-eyed Leonard Biggins, from Chorleywood, spotted that all the Union Flags were in fact flying upside down.
He said: "I would have thought they'd have had a quick check on the internet to find out. It appalls me that people don't know, it shows ignorance and disrespect.
"All the French ones are the right way up."
The correct way to display the Union Flag is with the broad white diagonal stripes at the top on the side nearest the flag pole.
Traditionally, flying an upside down Union Flag was a warning sign that there was trouble from enemy forces.
In 2009 former Prime Minister Gordon Brown fell foul of this by accidentally flying a small Union Flag upside down during a trade deal with Chinese premier Wen Jiabao.
Richard Neil, from Richard Neil Barbers, who helped organise the event, said: "It's been pointed out to us that they're hung up the wrong way and they will be changed.
"They were put up by volunteers, it was a genuine mistake, an oversight, they're hung vertically instead of horizontally and we didn't realise there was a wrong or right way.
"It's a bit annoying but what can you do."