It is clear that many close-voters use the "commonly available references" option as a catchall for questions that they just don't like for one reason or another, regardless of whether the answer to the question can actually be found in a commonly available reference. Not only is this capricious, unfriendly, and unfair, but by making it difficult for a reasonable person to determine what is or is not "off-topic" here, it actually encourages the submission of low-quality questions. This is exactly the situation that SE Community Coordinator Shog9 was hoping to avoid when he strongly urged us to clearly define what constitutes General Reference at this site—which we have never done. I therefore submit a proposal that, alone or in concert with the other proposal I am submitting today, will help resolve the current untenable situation.
I recommend that the "commonly available references" off-topic option be replaced with the following:
When selecting this option, the close-voter will be required to supply a URL from a set of whitelisted domains. Initially, the whitelist should include the following domains, taken from our standard list: dictionary.cambridge.org, dictionary.reference.com, thefreedictionary.com, merriam-webster.com, oxforddictionaries.com, etymonline.com, onelook.com, thesaurus.com. Others may be added as appropriate. If the voter does not supply a URL, or the URL is not from a whitelisted domain, the system shall not permit the vote to be submitted. Shog9 expressly endorsed the whitelist idea during the recent moderator election, which leads me to believe that the Stack Exchange software is likely to support it.
This change will not impose a significant burden on close-voters. If a voter cannot find an appropriate link within about 30 seconds of searching, then the question is not General Reference, almost by definition, and should not be closed as such. If we explain clearly why a question is GR and show how easily it can be answered, it is more likely to help dissuade the OP and others from asking similar questions in the future than just mysteriously closing questions with a link to three dozen sources of varying quality and purpose. If they end up bookmarking the reference we send them to and returning to it in the future, we win and they win.
Also see: Proposal: Add a “too basic”/“uninteresting” off-topic option. I've tried raising these issues before, and nothing came of it. It's time for some straightforward, actionable proposals that can be accepted or rejected. I have made two separate proposals because I believe they can be effective singly or together, and should be voted on independently of one another. Personally, I would prefer to enact this one and reject the other one, but anything would be preferable to the current practice of saying one thing and doing another. On a website that's explicitly devoted to communication, let's at least make a concerted effort to say what we mean and mean what we say.