Warnings
I just finished a story that ended with major character death and was about to add it to the "unwarned for character death" list when I went back to the beginning of the story and found that there was a warning, only that the warning was buried in the middle of the author's notes. Meanwhile, the character death warning provided by the archive (this was on AO3) was not used. Hell, the author didn't even bother to use the "author chooses not to use archive warnings" but instead chose "no archive warnings apply", which to me means that the story is safe to read, without having to slog through the author's (completely fucking pointless) author's notes.
In short, I was pissed.
So, new rule. If you post a story on an archive that has a character death warning option and choose not to use it, your story goes on this list. And you will go on my personal "never read fic from this author ever again list" because warnings matter to me as a reader and if they don't matter to you as a writer then I'm not going to risk reading your stories.