Things it took me a while to learn part 1, Stack Sizes

[Qar]

I thank again Bond for these superb posts. I have one question on pt 1:

You wrote:

"However, with this stack you should be restricting your open raising range a little bit more than 30+"

I might sound like a newbie, but what does that 30+ mean? You mean with a stack like 30-34 BB? Or how does that 30+ indicate a raising range?

(sorry if this sounds dumb).