I've been thinking about spoilers on this Wiki lately and I've come to a conclusion. Even though I personally don't like to spoil anything for anybody, the spoiler warnings add clutter, so I have decided that anything over a year old will go unmarked. This means spoilers for Twin Peaks and Twin Peaks: Fire Walk with Me will now begin to go unmarked.
The Secret History of Twin Peaks spoilers will remain marked until October 18, 2017.
The special case is Season 3, which will have its spoilers remain marked until one year after the final episode is aired.