Also a fatigue call only gets you out of working revenue flights, it does not guarantee immediate rest... they can keep you on duty and DHD you all over the map for as long as they want. In fact that's a common tactic used to discourage fatigue calls... you know you're going to have to wait 2+ hours for the relief crew and THEN ride a middle seat in a cabin full of disgruntled pax. Most folks would rather just fly the damn plane themselves, now, and get to bed sooner.