These stickers are to make readers aware of offensive content, just like all other media, TV, movies, music and video games do. A reader cannot make a choice not to read offensive content if they are not aware that it is in the book.
These stickers should only be placed on books by the owner of the book.
Harmful to Minors Warning Stickers - Sheet of 18 label size stickers (2.5" x
If you do not specify which type of sticker you want you will be given the sticker without the QR code.