For those that don't know the classification of print book is, in most part, regulated by the Book Industry Study Group. They're a trade association whose mission is to:
...create a more informed, empowered and efficient book industry. We’re committed to the development of effective industry-wide standards, best practices, research and events related to both physical and digital products that enhance relationships between all trading partners.They have a committee that overseas the BISAC Subject Heading List which classifies books. For instance Michael's Riyria Revelations fit into the following:
- FIC009020 FICTION / Fantasy / Epic
- FIC009030 FICTION / Fantasy / Historical
- FIC002000 FICTION / Action & Adventure
- FIC020000 FICTION / Men's Adventure
- FIC008000 FICTION / Sagas
If you are distributing books into bookstores you should make sure that the "primary BISAC" is on the back cover. For those that are traditionally published, when you review your cover design look for it near the left bottom of the back cover, and if it is not there, ask your publisher to add it. This is what tells them "where" in the store to place the book.
Michael's first small press failed to heed our warnings on putting a BISAC code on the book and "The Crown Conspiracy" was usually filed in the mystery section rather than fantasy....sigh.
It also probably doesn't hurt to place the BISAC in your book descriptions. Most readers don't know what they are or search for them but savvy readers, or those that work in bookstores might do searches on them to find new titles. Beside, it doesn't hurt and makes you look more professional. I would just place them at the bottom of the listing description.