I keep feeling like I'm not the fan everybody's looking for, at least wrt the warnings debate. Because while I'm fortunate enough to not have any real-life triggers, I also prefer my fic plastered with warnings and spoilers of every sort.
I do this with all narrative, actually, because I don't like suspense, and I find the first reading/viewing/hearing of a piece to be the least interesting. I connect much harder to characters once I know where they're going - and often I love sequences in hindsight that bored me the first time around, because I've since fallen in love with the people in them.
I also have fairly ironclad characterizations and interpretive patterns - so what ratcreature
's been talking about with the deeper issues relating to the Blair Sandburg haircut warnings definitely applies to me. I often have a very inflexible vision of canon - I'll read exceptionally good fic that falls outside it, but I'll put up with a lot more mediocrity when my preferred tropes are active. So my Daniel Jackson needs to be a gentle civilian geekboy, and my Jim Kirk is really damn smart and personally withdrawing, and my Frodo Baggins is unquestionably an adult as opposed to a teenager, and my Faith Lehane is something more than an evil bitch, and my Edward Elric is weird about his little brother.
Most fics that deviate from those characterizations get closed out of - they have to be really, really good for me to keep reading. And I like it when it's fairly obvious from the outset what character facets particular writers subscribe to, because I hate it when I read far enough in to get invested in the plot before I find out that an author's characterizations are just too different from my own for her story to work for me. And when warnings, descriptors, summaries, and author's notes give me such information right upfront, well, the happier I am.
I realized, in talking with my beta about my (almost finished I swear!) big postquest LotR fic, that the direction of the ending is not actually obvious in the narrative climax. And I thought about trying to hide the outcome, to keep any eventual readers in suspense. But then I realized that I would absolutely hate it if such a thing were done to me - particularly, in this case, because the question at hand involves the Grey Havens, which are traumatic enough that I need to have fair warning going in if they're going to happen as read. If I read through a whole novella thinking that there was hope only to have it snatched away from me - or vice versa - I remember, about two years ago, reading Middlemarch for the first time having only previously done Eliot's depressing stuff. I was sure until the end that everybody was going to die horribly, and I was shocked when they didn't. And I was less involved in Dorothea/Will than I might have been otherwise, because I was bracing myself all the time for a blow that never fell.
At any rate. As a rule, I don't click through to stories that don't have posted summaries, warnings, and indicators as to length. I want specific data before I commit! Am I really that unusual?
eta: just to make clear, I'm not making a political argument, or one of social responsibility, though I think those are important. I'm arguing from the practical - if your story doesn't have information tags all over it, why would I click that link? I'm arguing that information tags are good for fanwriters and fanreaders, as advertisements.