Are there any? Just vote for what you like, downvote what you don't?

Or is it like reddit where downvoting is for low quality content, not what you're disinterested in?

there are are only 2 rules I know of
1. don't create alt accounts to cheat the voting system
2. don't target downvote content because you don't like the uploader

Also, even though it's not explicitly stated, don't downvote content you dislike when you can easily blacklist it. This includes artists, fetishes (e.g., gore, scat, watersports, etc.), and any other tag you can find.

Use the Blacklist, it is there for the benefit of everyone.

I also have a question about it. I know target down voting is not allowed. But some days ago, I saw someone posting a couple stupid statements under one post. I was about to down vote all of them, but thought about this rule. Would it apply in this situation too?

thegreatwolfgang said:
Also, even though it's not explicitly stated, don't downvote content you dislike when you can easily blacklist it. This includes artists, fetishes (e.g., gore, scat, watersports, etc.), and any other tag you can find.

Use the Blacklist, it is there for the benefit of everyone.

It's understandable if there's a few images that get downvoted, but once you start seeing it multiple times check if there's a tag you can blacklist. Save yourself the annoyance.

dubsthefox said:
I also have a question about it. I know target down voting is not allowed. But some days ago, I saw someone posting a couple stupid statements under one post. I was about to down vote all of them, but thought about this rule. Would it apply in this situation too?

Well, if the person is being stupid under a single post, then just go ahead and downvote (just like you would if there is roleplay, creepy comments, spam, etc.).
What is not encouraged is that you start downvoting every single comment they have posted, that would be grounds of abuse and potentially harassment.
If all they have ever posted is bigoted comments, then you might want to consider reporting the user.