
This is the 12th edition of Robert's Rules, and takes precedence over all earlier editions for WSFS, Westercon, and most other groups that have defined their parliamentary authority in the recommended way. I've never read any of the In Brief versions, but this 3rd edition was issued in parallel with the 12th edition of the Big Book, and I went ahead and bought a copy to review to see just how it gives a shorter version of RONR. The Big Book is comprehensive, but that also can make it very intimidating.
Time to start reading to see if anything has changed that affects Westercon and WSFS.