Do we have a specific length of time before you don't have to use spoiler code anymore? Personally, I'd say after six months it's probably not really necessary anymore. By that point everybody who wants the read the book will have had plenty of time, and people (like me) who haven't read the book yet, should be aware that they are in the minority and that discussion of the book's events will probably be spreading to other threads.
That's a good question. I agree that after a certain point it's not necessary to post spoiler tags. I've not read every book that's out there, but I don't mind if people talk about them. The same is true for the TV series. Not everyone has seen every Trek
spin-off. Do we have to use the spoiler tag for these discussions, too? It's better if people just avoid the threads they don't want to read. It's not hard to avoid clicking on a topic if it's not interesting.