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.
Vader's down...but not out! When the Sith Lord faces an entire Rebel fleet on his own, and is sent crashing onto a nearby planet, two of the biggest titles in comics collide in the first crossover of the new Marvel age of Star Wars! Will the Rebels seize this opportunity to put an end to one of their greatest enemies - or will they be made to feel the full power of the Dark Side? Find out as the classic cast clashes with all-new favorites Doctor Aphra, Triple-Zero, Beetee and Black Krrsantan! Meanwhile, the natives of the planet Shu-Torun are revolting. And there's no way the Empire will stand for that. The imperial march of Darth Vader continues!