Content flags give parents better information
A content flag is a way to name something inside a book that may matter to your family. Violence, language, romance, sexual content, occult themes, substance use, fear, death, grief, and self-harm are all examples of categories parents may want to check before a child reads.
The point is information. Shelf Checkout shows what is present, then lets the parent decide what to do with it. Different families will make different calls, and the same family may make different calls for different children.