Political rivals. Badminton adversaries. What to know about Taiwan-China

PARIS − Badminton is a hugely popular sport in both Taiwan and China. At the Paris Olympics , two incidents in as many days involving the sport's spectators reflects those place's uneasy rivalry on the world stage.

A Taiwan badminton supporter who was holding up a sign that read, "Let’s go Taiwan," had it ripped from her hands and torn up Sunday during the men's doubles badminton final. Wang Chi-Lin and Lee Yang of Taiwan beat China's Liang Weikeng and Wang Chang in a three-game thriller to win the gold medal in the event. A towel with a similar sentiment was also stolen off a Taiwan fan during the match, according to reports .

The incidents prompted Taiwan’s government on Monday to call on French authorities to launch an investigation. It followed a separate report on Friday that saw a spectator who was holding up a green banner that read, "Taiwan go for it," removed from a Paris badminton venue during Taiwan player Chou Tien Chen's match against India’s Lakshya Sen.

Here's what to know about Taiwan and China at the Olympics.

First of all, Taiwan isn't called Taiwan at the Olympics

China's government has claimed sovereignty over self-ruled Taiwan since a civil war in China in the 1940s, when Chiang Kai-shek’s Nationalists lost to Mao Zedong’s Communists and rebased their government in Taiwan. Beijing uses its global clout today to require that the International Olympic Committee let Taiwan, known internationally as an island-territory, join Olympic events only as "Chinese Taipei" because the label implies a link to China.

What about the flag? And the flag anthem?

Instead of Taiwan's official banner, its Olympic athletes wear a white-colored Chinese Taipei flag on their uniforms. It features a five-petal flower encircled by the Olympic rings. Taiwan's flag anthem is banned from Olympic Games. On Sunday, for only the second time in Olympic history − the other time was at the Tokyo Summer Olympics − Taiwans's flag anthem was played during the medals ceremony. Crucially, however, the anthem's lyrics were changed for the performance so as not to upset China. It's not clear if the ceremony was broadcast in China.

Yes, Taiwan is in the Olympics: What that means for island's Winter Games

How have Olympic organizers reacted?

International Olympic Committee spokesman Mark Adams said in a press conference Monday that there were "clear rules," drafted in 1981, governing Taiwan's participation as Chinese Taipei. He also noted that spectators are not permitted to bring banners to Olympic events. "You can see how this can lead into: 'If that's allowed then why not this?' That is why the rules are quite strict. We have to try to bring 206 national Olympic committees together in one place. It is quite a tough ask," he said. The Badminton World Federation did not respond to a comment request.

Green, the color of the stolen towel, is associated with Taiwan’s ruling Democratic Progressive Party. The DDP has sought to transition Taiwan toward full independence from China, leading to increasing military threats from Beijing.

This article originally appeared on USA TODAY: Political rivals. Badminton adversaries. What to know about Taiwan-China