When it comes to airline ticket rules, the devil isn?t in the details. The devil is the details.

You?ll find Old Nick in something called the ticket tariff, which is a massive, rambling and often incomprehensible document that passengers rarely see in its entirety.

Why? Partly because they tell you what you already know ? for example, that you have to pay a fee if you want to change your ticket ? and partly because it just doesn?t concern you. For instance, some tariff rules talk about special fares for police officers or firefighters, which a vast majority of passengers wouldn?t care about.

But there?s another reason why you won?t see these rules: Airlines would rather you not know about them. That?s because they like to bury all kinds of restrictions in the fine print, hoping their passenger won?t read them until it?s too late.

Get the full story at MSNBC