When one has feelings to share and takes to Facebook to do so. Instead of writing out what one actually needs to say, they write something cryptic that prompts others to ask "what's wrong." This is usually when the Vaguebooker replies with another Vaguebook reply such as "DM me" or "don't feel like talking about it." This will then prompt the inquirer to not give a shit.
Kelly had a bad week, so she took to Facebook to do some vaguebooking. "Really wish things turned out differently."
noun: An intentionally vague or one-worded status update, alluding to something else. This could be an inside joke, or anything meant for only a few people. More simply, it could be a plea for someone to comment. Such as "pointless", "frustrated", or any inside joke.
Did you see Jeremy's vaguebook? All it said was 'pointless'.