I think that is definitely a good rule to have. I think it’s very true that we don't all like the same things and shouldn't be expected to read what we don’t like. Back in the day, I really didn’t want to read any relationships. I was much closer to ace then (and there’s a lot of good ace fics these days which is nice). We’d need specific tagging to make sure people knew what they were in for. I also think participation has to be optional. Nothing like a requirement to make me not want to do it!