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 unstoppable march of the Dark Lord of the Sith continues! The natives of the planet Shu-Torun are revolting. And there's no way the Empire will stand for that. Darth Vader is tasked with leading a military assault against Shu-Torun! Could it be that his rise to glory has begun? But who will follow Vader into war? Would you? Then again, it's better to fight alongside Vader than against him. That's a lesson that the Ore Barons are about to learn…