Why the "+" character in the question title in superuser.com causes the message saying "This post does not meet our quality standards" when trying to post? Is this behavior documented somewhere? I've just spent 10 minutes trying to figure out what's wrong with my question.
It's not really "+" that's hurting you there. It's that there wasn't much else to your title beyond "+". See random's edit - that's what your title should have been: a short summary of the question you were asking.
You're allowed 150 characters for titles. Don't be afraid to use 'em next time...