Every correction we make to a published book is logged here, with the date. If a rule changes between printings, this is where it is recorded.
No corrections logged yet.
That is not a claim that our books are perfect — it means none of the books above has needed a correction since publication. When one does, it appears here with the date, the book, and what changed. Nothing is quietly edited away.
Each app shows the version of its question bank and the date its sources were last checked, on its About screen. When an app’s content is updated, your scores and your place in the study plan are kept.
