Question about mature stories
 

Hey everyone not sure if this is the right place to ask but I was wondering what is the difference and requirements of the 18+ Mature stories forum as after having a read through some of the stories, some of them are mature and others are quite tame even compared to the normal story forums and vice versa. So I was wondering what would be the basis to upload your story to the mature forum or is it just a matter of opinion? Thank you.