Anonymous wrote:This has changed over time. "On the books" means "on the record" and was always used to mean "completed."(It also has the meaning of "scheduled," but that's a distinct idiom.)However, over the past 15 years "in the books" has been used more and more frequently (to the annoyance of many) to mean "completed" and now seems to be the more common version of that expression, to the point where many people are not aware of the shift. Similar to what is happening with "based on" vs "based off"
Do you have a cite for that? I’m pretty old and was raised by someone born in the 19th century and also read a lot of older literature, and I don’t think I’ve ever heard “on the books” used in that way (to mean competed).