Bookbinding substances and requisites; stapling, binding and covering devices intended for office use; staples, staple cassettes and binding substances and materials suited for stapling, binding or covering device requisites in non-metallic cases and not intended for industrial use; staples, staple cassettes and binding substances and materials suited for stapling, binding or covering device requisites and intended for office or household use; covers of books, picture books, magazines, writing pads, binders and brochures suited for stapling, binding or covering device requisites