Until they have a filter in place for people to choose from the only things I think should be flagged are blatant plagiarism of other steemit posts. If I work hard and make a great post, and you take my post, copy and paste it and post it as your own.

Or obvious first IMAGES as graphic porn, or violence without a warning and allowing the person to OPT in.

If they setup a filter of some sort so you could opt in to seeing those images permanently then I believe no warning would be necessary NSFW or something like that.

At the moment it is beta and no such thing is there.

There are a lot of down vote brigades happening, and hate, and anger on things I believe people are missing.

https://steemit.com/steemit/@dwinblood/that-person-is-not-worthy-neither-are-you-neither-am-i-but-who-is-do-things-my-way-or-else

I just wrote that... at the bottom I link to an article I wrote this weekend about down vote brigades that I think ties into and is relevant to censorship.