...on fanfiction/RPF/Original works. I absolutely hate when people want you to tag it for rape or child abuse or even something like offensive language.
No. I will never do that. And it's not because I want to offend people or anything, but mostly just because that's a risk you are taking when you read anything new. Most books in the bookstore aren't going to warn you about every potentially disturbing thing inside. Why? Because it's essentially a list of spoilers. If you go in knowing that there will be an abusive relationship or homophobia than you will already be pre-guessing the events.
As an author I want to keep my plot twists just that, plot twists. A lot of times the things people warn about were character developing issues that the reader is supposed to discover over time as the story unfolds. By tagging everything like that you are doing your work a disservice and robbing the reader of that unfolding experience. So I will never tag my work. I will give it an appropriate rating, but my content will remain a secret until that time when I decide to disclose it, and believe it or not the reading experience will be better for it. If you come across something that disturbs you, than simply turn away. Skim over it or just abandon the story entirely if it's really not your cup of tea. That's fine. And that's no different than what you would do with any other book from the library.
All these warning tags do is remind me that we live in a culture that seems terrified of even accidentally offending someone else, when the truth is that everybody is going to be offended by something at some point in their lives. It's inescapable. This post will probably offend some of you and while it wasn't my goal, I don't actually care. It's good to be offended sometimes because that's the only way you're ever going to learn how to deal with it. The world is going to offend you. Learn to cope. And in this case, learn how to handle coming across a potentially sensitive subject in a piece of literature. The world doesn't have to edit itself for you.