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.
Tash, Zak, and Uncle Hoole stop on the planet Ithor for supplies, including a mineral the Shroud needs for its engines. The mineral isn't available on Ithor, but one of the Ithorians knows where they can find it--on a mining colony in the middle of a space slug-filled asteroid belt. The journey to the colony is filled with many dangers. But nothing prepares Hoole, Tash, and Zak for what they meet when they reach their destination. An ancient life-form has been released from its tomb. It has lurked there, waiting, for many years. It cannot be seen. It is made from pure evil. And its name is Spore.