To make a statement on the current debate, I think a list of mandatory CW would be a good start on the instance level.
You can't enforce a rule if there's no explicit rule; you can't expect someone to CW everything you think deserve one without making it explicit.

So what would you want on that list?

@CobaltVelvet Porn, real-life gore (think pictures of a terrorist attack or a warzone), videogames or TV series spoilers

@jkb That's about what I had in mind too!