Why the warning "Selector specificity 0, 2, 0"?

Question

My Visual Studio keeps displaying the following warning (I think it's actually the Web Essentials plugin that produces it) but I'm not really clear why this is a problem? Can some explain please?

PS, Yes I understand what specificity is and how to calculate it, I just don't know why a specificity of 0,2,0 is a problem?

Answer 1

The above isn't the error message, it's standard hovering info when you move your mouse over a selector with WE. However, the problem you're facing is probably the same selector being specified twice in the same file.