Are there descriptions of the hubs themselves on Habré?

Question

Habr

For example, the Black Hole hub - what is it?
Don't get me wrong, I intuitively understand. But is there an official description to more accurately determine which articles the hub contains and which does not? Sometimes strange names of hubs come across.
For example, "Ecology" - it seems clear, you don't need to look at the definition. And some "Brain" is not entirely clear at first glance, what specifically.