Why are some servers highlighted in yellow and others aren't?

[JJKAY645]

What I mean is, some servers have their name in highlighted yellow and most do not. Why is this?

[aleksb385]

If a server is highlighted, it means that the ClassiCube administration considers it more unique than the rest of the servers, either because of a certain gamemode it offers or something else that's noteworthy enough to make it different to other servers