BISAC_Subject_Headings
The BISAC Subject Headings are a method to classify books that is geared towards bookstores. It is mainly used by the Northern American booktrade, and online sellers like Barnes & Noble, Amazon and Baker & Taylor. The Book Industry Study Group maintains the BISAC system.[1]
BISAC classifies all works by topics. It does not favor Western culture, history and religion as much as the Dewey Decimal Classification used by many libraries.
All topics and sub-topics are ordered alphabetically, which also encompasses works of fiction. The BISAC's numbering scheme allows for a later introduction of new topics between already established ones.[2]
Books can fall into several categories. In this case, BISG recommends that no more than three categories should be chosen for a single book, and the main category should be the one that best describes the book's contents.[2]