I think I've heard it used reasonably, but I can't really remember the specifics. Basically, it's when the cause for the exception follows naturally from the l

I think I've heard it used reasonably, but I can't really remember the specifics. Basically, it's when the cause for the exception follows naturally from the logic behind the rule. Contrived example: If something holds for most birds, an exception for penguins might qualify. In any case, this is just an exception that breaks the rule.