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.
Star Wars: Rebel Heist is a fun adventure featuring the main foursome, in between Episodes 4 and 5, as individually they participate in separate steps to pull of a heist and-well, giving away too much of what they're doing might spoil the fun. But they're not the ones telling this story. Each of them encounter four different individuals. These four individuals get involved in their heist and learn a valuable lesson about what it means to be a Rebel, defying the Empire, and risking your life for what you believe in and to help others.