I suggest renaming it from "How many invite codes can I generate?" to "How many invite codes can I generate? How can I get more invite codes?" or something similar.
Long, yes, but it's fairly common to have users saying "I've used up my free code and the FAQ doesn't say how I can get more if I don't want to pay," such as here and here and here.
Sure, we'd still have users asking how they can get more free codes, but I figure that renaming the FAQ might well catch a few. I think that the FAQ could also be rewritten to be a little more definite on Free users only getting one automatic code, but I have to go concentrate on the Research Paper That Owns My Soul right now rather than the FAQ.