Chad and Romania are situated on separate continents and share few historical or geographical links. They don’t even have an embassy in each other’s country.
The two countries rarely come up in the same sentence. That is, unless you’re discussing their flags.
Aside from slight variations in color shading, the two countries’ flags appear identical — an observation Tesla CEO Elon Musk appears to have just discovered and shared with Twitter.
According to the online Encyclopedia Britannica, Romania initially displayed a flag with horizontal stripes of blue, yellow, and red before settling on its current vertical design in 1861.
Chad decided on its own flag design after it achieved independence from France in 1959.
The country initially considered a green, yellow, and red design but quickly discovered Mali had already taken the same pattern. It then swapped the green for the blue — inadvertently creating a flag that was almost identical to Romania’s.
Chad’s flag is not the only one to resemble other flags — here are some other examples
The flag of Mali, the country Chad tried to avoid copying, is similar to Senegal’s — a single green star in the middle appears to separate the two flags. Guinea’s also replicates Mali’s design but is reversed.
Both Indonesia and Monaco fly two horizontal stripes: red over white. Poland similarly flies white over red.
Ireland and Ivory Coast share the same design, but it is flipped on the flagpole.
All of these similarities may have stemmed from coincidence, but other flags have a specific reason for slight variations to a theme.
Ecuador, Venezuela, and Colombia all sport the same-colored horizontal stripes, but that’s because they used to be part of the same country of Gran Colombia, which dissolved in 1822, according to Britannica.
This article originally appeared on Business Insider. Follow @BusinessInsider on Twitter.