Thanks for reaching out.
The 18+ tag is meant to notify readers, especially those underage that the book has explicit content.
Your book is considered adult content if it has explicit sex, violent scenes and/or words and we want to protect our young readers from such content.
So before publishing your book, if it has any of the above, please tick the Adult(18+) box. Failure to do so means we will take down your book.
If you have any more questions, you can hit the reply button or check out our Help Centre as we have tons of articles that will help you!