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Offsite: Editeur's Thema page -- see Basic Instructions.PDF and full code list

Thema Subject Categories

A book's subject is not considered to be hierarchical – every Thema code used describes the book' content and can be used as guide for someone seeking information on a subject.   But Thema codes themselves are hierarchical and contain a reference to a higher level starting from their first letter representing one of (currently) 20 broad subject areas.   As example, all Fiction subject codes start with F.  Codes starting with FB are a subdivision of Fiction for " general & literary" while FD is "Speculative fiction."  FBA, and FBC subdivides "general & literary" into "Modern & contemporary fiction" and "Classic fiction" while FD "Speculative fiction" is subdivided as FDB"Dystopian & utopian fiction" and FDK"Alternative history fiction"   A retailer (or other metadata user) can enter at any of those levels and select a FBC as "Fiction" or "general & literary fiction" or "Modern & contemporary fiction".  


  • Publishers should always choose the most specific code. There is no reason to list the entire hierarchy as separate codes.
    (If you feel you need list all parts of hierarchy, read the Notes for the specific subjects as there may be other options you haven't considered.) 
  • A code applies or it doesn't and the more specific you are in a Subject code, the more a retailer knows about the book.  
  • Volume is not helpful. A specific code says more than a spread of generalizations can, but use as many specific codes as necessary to describe the book's content.
  • Don't rely on your software's drop down menu. Get and use the full code list so you an access the notes and references.  
    (Update your code lists regularly, at minimum yearly each spring after the new version release.)

Main Subject

Retailers, at least in North America and the UK, need one subject code called out as the Main subject (the same as BISAC).  The best way to think about that is out of all the subjects codes that accurately describes this book, which of these codes would direct this book to the most interested buyer? Buyers and other selection professionals and librarians normally work as subject area specialists.  A main subject is a pointer to the most appropriate professional to judge the book's quality. For their convenience publishers provide ONE Thema Subject Code (never a qualifier and never more than one code).  This is identical in all respects to BISAC coding.  Calling out one subject for this purpose doesn't change that a book's overall subject or that all the codes apply.


  • A Main Subject is always a single Subject code (never a Qualifier and never multiple subject codes)

Subject Categories vs Qualifier Codes

In addition to Subject codes, Thema also supports six numbered Qualifier lists: 


To contribute feedback, email us at

Subject codes can add meaning to subjects too

In using the BISAC Subject Codes there are a number of things you shouldn't do – one being mix Fiction and Nonfiction codes or mix codes from Juvenile, Young Adult and the balance (general trade adult).   Don't dilute the message.


Used appropriately and with clarity any code can be combined. Remember that a retailer or a consumer has to be able to use the classification, it must be accurate, and practically you are more likely to use non-fiction codes to add depth to fiction than the reverse, but Thema coding allows flexibility

Sample Thema in an ONIX Record

Thema ONIX Sample

Get Thema downloads