At the moment, the fact that “general reference” questions are inappropriate isn’t very prominent in the FAQ. As far as I can see, it’s only mentioned in the section “Why are some questions closed?”, which I would imagine many people may only read after they have a question closed.
Would it make sense to also mention it in a section that users are more likely to read before asking their first question — eg the section “What shouldn’t I ask here?” It could be worded something like:
“General reference” — questions that are too basic. If a single query in a well-known freely-available reference completely answers your question (for instance, searching for your question or a key word from it in Google, Wikipedia, or Dictionary.com), then you don’t need to ask it here. If you want more details than such sources give, then say so — make clear, in your question, what you want to know. Some guidelines.
I had a memory of a blog post where Jeff gave more general guidelines on what exactly makes a question GR, or saves it from that fate, but I can’t find that post now.
(Thanks to @Waggers for raising the issue here.)