BISAC 2015 support.
You can now use the 2015 edition of the BISAC Subject Headings to categorize your books on iBooks. The newly added Young Adult Fiction and Young Adult Nonfiction subjects should be used for classifying titles aimed at young adults (ages 12-18). Per Book Industry Study Group (BISG) standards, young adult works should not be assigned subjects from any other sections.
To reach the audience you have in mind, choose the most specific primary subject category that best fits your book. Remember, you must choose at least one primary subject category when submitting your book.
For more information on BISAC, visit www.bisg.org.