I just spotted this question on the front page, and I think this one and it's siblings listed in there should be closed/locked like their relatives (e.g.. the command line tools on Windows). What do you think?
I've always had an aversion to "hidden features" stuff. You'll find that most of the answers to those questions are about well known and well documented stuff. It would be hard to find something in the answers that genuinely qualified as a hidden feature. I see no value in any of those "questions" and would much prefer to see them vapourised.
The m.SO question posted by Mark is from July of last year; in October of last year, a number of SO's "hidden features" questions were closed and locked - and even as recently as a week ago, the one for Python was (re)closed.
The majority of their "big" hidden features questions seem to be closed and/or locked, but some are not; it doesn't seem to be quite a settled debate.
But, hey: we're not Stack Overflow, and I think we can make this one idiosyncrasy that we choose not to inherit.