The content guidelines only mention "if the intended audience is 17 and up". This is really vague and offers us very little to go on. So basically all I can do is speculate. As I am new to this site, the prudent thing to do would be to ignore my word entirely and wait for someone more knowledgeable to chip in.
That said, let's speculate. ScribbleHub is hosted in the US, and an unofficial demographics poll places nearly half of the audience in the US as well, so a bias towards the US definition of things is probably prudent. To make it easier to think about, "audience 17 and up" is equivalent to an R rating. The most well-known definition of an R rating is the one from the MPAA. It roughly defines strong language as:
- multiple instances of sexual expletives in situations that do not absolutely require said words;
- a single instance of a sexual expletive in a sexual context;
- every handful of less severe expletives generally counts as one instance of the big no-no words.
That might sound absurdly strict, especially if you come from a non-US-centric culture where expletives aren't as harshly frowned upon. Personally, as one of those non-US-centric people, I've learned to keep my mouth shut and rate as an American. I'm simply way too much of a chickenshit to risk getting flamed solely because I disagree with the US definition of an R rating.
On the other hand, Scribblehub is a small site, and the definition in the content guidelines is vague, maybe purposefully so. This might grant you significantly more leeway than what I outlined. I'm not the mods, so don't take my word on that.
For completeness sake, here are similar definitions of what constitutes gore and sex:
- either lots of "fake gore" (think really bloody action movie) or a small amount of highly realistic gore (think horror movie) grants an R rating.
- Sexually-themed nudity (without sex), or actual sex also earns you an R.
Finally, a little tongue-in-cheek, how do you avoid content warnings:
- Fake swears aren't swearing. Your characters can talk about fraggin' shizz all day long and no one will care;
- blood is only gory if it's red;
- getting really, really, really, really cuddly while still mostly dressed isn't sex