The BSW4/ASW4 notation was used in the timeline of the second edition of A Guide to the Star Wars Universe and The Essential Guide to Vehicles and Vessels.The Essential Guide to Planets and Moons eschewed acronyms altogether and listed dates as YEARS, with 0 YEARS being the events depicted in Star Wars Episode IV.
The first Essential Guide to use the BBY/ABY notation was The Essential Chronology.
This practice was continued in The Essential Guide to Alien Species and beyond.
When you have a community filled with girl gamers, you get a lot of questions about it.
Sometimes we get asked if guys are allowed in, or if we could make an exception just for them.
With the exception of the Ruusan Reformation, the later epochs were all within the same century and stemmed from the events and upheavals surrounding the rise and fall of the Galactic Empire.