[I hope this is the place for this.]
Mentioned in a number of places I've heard of Craftworld specific rules for the 5 main Eldar armies. Though I've never been able to find what these rules are exactly, I thought I might make one for my own Craftworld, more to complement fluff than any real advantage.

Honoured dead: Bcause of the ferocious nature of the craftworlds fighters the ressurection of warriors is seen as an honour for them to continue fighting, attacking in a rage even when blinded. When a Wraithlord or Wraithguard rolls 1 on their wraithsight roll a second d6. If it is a 1 or 2, they must move 6" in the direction they moved last turn. If a 3 or 4, target the nearest enemy unit normally. If a 5 or 6, target the nearest friendly unit. If the model moves as a result of rolling a 1 or 2 and lands on difficult terrain, they must take a dangerous terrain test from to their reckless actions.

That's the fist draft anyway. I thought the wraithsight was as good a target as any but didn't want to make it obsolete, just more interesting. Bloodthirsty warriors in life may not let altered vision stop them in death but I didn't want to take away the gamble that comes with the default rule (stopping in their tracks to get sorted out). This way they may just stumble on and keep shooting, but may end up killing team mates.