I come from a heavily warned fandom (The Sentinel), where everything is warned. If a writer doesn't put "proper" warnings on an archived story, they will hear it many times over. So... I warn in Sentinel about everything. In Pros, I do what I do with a zine, where there are almost no warnings: I read the last page. I know many people find that horrible, but for me, unless it's a 'B/D alive and happy ending', I don't want to read it. And it needs to be slash for me. So I don't "need" warnings, but I appreciate them. I'm a darned good skimmer.

What writers have taken to doing in Sentinel, since the warning "I can't warn or it will give away the plot" didn't go over very well, is to put any relevant warnings, including major death, torture, etc, after The End. Then a reader has the choice to go to the end and read the warnings, or to start from "It was a dark and stormy night..." and enjoy the story with being spoiled.