A rapist doesn't care whether the victim enjoys what happens. It is purely about control, not about sex.

I think that's a good definition. Rape is about power and hurting the victim, while non-con is actually about sex and control.

But I think that's a problem with most warnings in fanfiction. People just can't agree about what they mean. It starts with "yaoi" where people mean "shounen-ai". And of course there's the problem of when to label a story Harry/Draco or Draco/Harry. And of course the list of potential warning is so long, it's really hard to figure out which apply to your story.