Several questions that get asked in some form every day (Mod_rewrite, Regex, How to parse HTML...) can't be rightfully closed as exact duplicate of anything else, because they always present an individual use case, and a valid question.
This renders the whole idea of having reference questions for oft-asked topics like this one a bit moot, because there is no valid way to point to them.
Therefore, how about introducing a "Trivial variation of..." close reason? It would work just like the "close as dupe" dialogue. Like so:
It would offer the same dialog to point out the original question like the "close as dupe" dialogue. There might be potential for tweaking the dialogue later, like showing the most often pointed out originals in a tag at the top of the list - but that's not a requirement.
I realize this is a bit of an RTFM for the asker, but I haven't seen a better suggestion to deal with the influx of these kinds of questions yet. They're very tiring. Plus, in the best case, this directs the asker to a general guide that will help them.