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.
The Rebel Alliance sets their sights on strengthening their forces by growing their numbers. But with a greater number of supporters comes dissidence and difficulty - can Leia, along with Han and Luke's help, forge one alliance from many factions?