I see a lot of signs at work and in public places that say something like "This area is off limits to unauthorized personnel".  This is an examples of a rhetorical tautology, i.e. "an unnecessary (and usually unintentional) repetition of meaning, using different words that effectively say the same thing twice".  The area is off limits because the personnel aren't authorized to be there.  The personnel aren't authorized to be there because it's off limits to them.  And so on. #language