When we released The Ephemeris Omnibus 2013, we made a few changes to the rules from the core rulebook. We don't want to make it necessary for everyone to buy this supplement if they don't want to, and since so many people have recently purchased the core rulebook, we wanted to make the rule changes available to all of those people for free.

This small publication doesn't list all of the changes, but it does include the most important ones.