Recently, I've been considering the tags that I associate to my stories and I find that there are a few I don't fully understand. I'm posting to request clarification on some of these. For instance:

1. What is nc? Is it the same as non consensual? If so, how does it vary from reluctant?

2. What are the differences between Extreme, Heavy, Serious, Hardcore and Violent? Are there some specific type of content which are applicable for one of those over any of the others?

3. Young and teen. I am under the impression than underage characters are frowned upon. I'm considering having a background character or antagonist as a younger character in one of my stories and I'm wondering if this comes under one of these tags or is not allowed outright.