BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
The Youtini Expanded Universe Ranking system is a 1-5 scale that ranks EU book quality, difficulty, and importance. Books closer to Level 1 are easier to read and understand, more important, and of higher quality.
It's an all-out war as the Sith emperor returns from the dead-stronger, more evil, more determined, and prepared to unleash a new secret weapon upon the galaxy! Roan Fel's loyalist Imperials, the Galactic Alliance, and the Jedi are all on the defensive-reeling from the attacks by the unified Sith.
But Cade Skywalker has his own plans for this war--all this time spent running from his legacy has finally shown him that he can't run . . . and he must stand alone against Darth Krayt!