Excellent knowledge of C++ [closed]

Question

I recently saw a recruiting page for a software company where one of the requirements was "Excellent knowledge of C++."

Now, I know this somehow implies as expert knowledge of C++, but where exactly does expert knowledge fit into. Is it the knowledge and experience of (let's say) eight years of programming in the language, having and knowing the ins and outs of a specific domain. Or, is it a more brush-up, surface approach to one or more domains and a at the same time a more detailed understanding of the whole language?

For example, you cannot be an expert at writing system drivers and game engines at the same time. So, where does this excellent or expert knowledge fit into?