I tend, generally, to only warn for major character death/death of the one (or both) of the pairing in question; although I have on one occasion warned for other canon character death.
There has also been discussion as to whether you should warn for the death or a major character, when that major character is not part of your pairing. For example, in a Fraser/Vecchio story should the death of Kowalski be warned for? In a Gibbs/Ducky story, should the death of DiNozzo be warned for? My personal feeling here is that I normally wouldn't warn for the death of my non-pairing character.
And also what about stories that involve the death of a character who has been killed in canon? For example, every time a NCIS story is written that involves Kate's death, should that carry a death warning? Or is it dependant on whether Kate actually dies in the story, or whether the story is set immediately after her death? Or again, does it depend on whether Kate is part of your pairing?
I was wondering whether there was any kind of general consensus, so here be a poll:
For whose death would you generally warn/expect to be warned in a fanfic story?
Should there be a warning, in multi-pairing fandoms, for the death of a major character who isn't part of your pairing?
Should there be a warning for the death of a character who dies in canon?