Design secrets and oddities of the world's flags
When the flags of the world got their spotlight moment at this year's Winter Olympics in PyeongChang, they were unified by two principles: sportsmanship and uniformity.
"Flags come in lots of different shapes, not just square and rectangular, and the rectangular ones are different shapes. They can be 2 by 3, like France, or 10 by 19, like the American one," Graham Bartram, an expert at the Flag Institute, the world's largest flag organization, said in a phone interview.
National flags come in more than a dozen different ratios, from the perfectly square Switzerland to the very stretched Qatar, the only flag whose width is more than twice its height. But at the Olympics, for the sake of practicality, they are all the same.
"It used to be that the ratio was made to follow the one of the host country, but now it's been standardized to the Olympic flag, so at ceremonies they are all 2 by 3," said Bartram.
The only exception in Nepal, whose flag is not even quadrilateral. It is composed of two combined triangles, and allowed to fly proudly untouched (although not in PyeongChang, where Nepal did not compete.)
Korea's unification flag
But perhaps the most significant unification came from North and South Korea, which marched together under one flag. It has happened before -- even at the Olympics, in 2000, 2004 and 2006 -- but it struck a chord in the current political climate.
The Korea Unification Flag has a simple design: a blue silhouette of the Korean peninsula on a white background. But in some versions of it, if you look closely, you can just about make out a dot on the right, meant to represent a small group of disputed islets known as the Liancourt Rocks. They are controlled by South Korea -- which calls them "Dokdo" -- but also claimed by Japan -- which refers to them as "Takeshima."
Flags with the dot were seen at a practice hockey match just days before the Olympics, fueling diplomatic tensions between South Korea and Japan, which opened a permanent exhibition in Tokyo last month illustrating Takeshima and other territories that fuel separate disputes with China. In response to Japan's complaints, South Korea's unification ministry confirmed that a flag without the dot was used during the games, as approved by the International Olympic Committee.
It was the last flag to enter the parade, as the host country traditionally closes it. Greece, the nation who originated the Olympic Games, always opens the parade, while the rest of the order is alphabetical according to the language of the host nation. This led to an interesting opening quintet, based on the Korean alphabet: Greece, Ghana, Nigeria (making its Winter Olympics debut), South Africa, Netherlands.
A shade of blue
Just 91 flags paraded in PyeongChang, as opposed to the 207 seen at the 2016 Summer games in Rio. However, two of those flown in Rio were virtually identical: Chad and Romania.
"What happened was that once communist rule ended, Romania got rid of a badge it had in the middle, but then Chad complained, as that made it identical to their flag," Bartram said. (In reality, the blue strip of Chad's flag is darker than that of Romania's.)
Rules and customs around flag design make duplicates unlikely, but several national flags are quite similar. That's probably why a unique design stands out, as is the case of the UK's Union Jack.
"It's a very complicated design, it takes a lot of time to draw it. It's rotationally symmetrical -- not horizontally or vertically symmetrical -- but it's unique. There's not quite anything like it," Bartram said. "Even America has strong similarities with Liberia and Puerto Rico, but with the Union Jack one never wonders which flag it is. From a design point of view, it's very powerful and recognizable."
According to Bartram, however, the most remarkable flag design belongs to South Africa.
"Technically, it breaks all the rules. Flags are only meant to have three colors, but this one has six, and it works," he said.
"Usually a flag is a reflection of the country, it comes after the country does, but this one was part of the creation of the country itself. It had a job to do. It was created to bring people together, and its symbolism indicates that. It actually helped create the country, and that's very powerful."