Thema Basics: Subject Categories, Qualifier Codes, National Qualifier Lists

Related pages

Thema Subject Codes

Thema ONIX Sample

BISAC to Thema Translator

Thema Implementation: Practical Considerations

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".  

The full Thema code list available from EDItEUR provides a "Notes" section and Related Codes column with additional instruction and references.  So FDK "Alternative history fiction" is clarified by a text instruction "Use for any fiction, apart from Fantasy or SF, set in an imagined world that might have emerged had key historical events happened differently eg outcome of WW2".  This seems a bit confusing in that these instructions say codes are hierarchical and this internal supplementary note says "any fiction, apart from Fantasy or SF".  It's not because if you use the Notes it will clarify that Thema makes a clear distinction between Fantasy, Science Fiction and Speculative fiction.  The notes, shared by all users, make Thema's scheme plain in practical and illustrated ways.

  • 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.

It's easier to understand in a concrete example and the Thema ONIX Sample gives detail.

  • 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: 

  1. Geographical
  2. Language
  3. Time Period
  4. Educational Purpose
  5. Interest Age & Special Interest
  6. Style

Some subjects and some books require clarification of their subject(s).  The Thema Subject Category notes will often reference that the code is typically supported by a geographical, language, time or style qualifier.  Their use is no different than assigning a Subject category – use any qualifier that applies to book's content and be as specific as possible: A cookbook can refer to a national cuisine; Architecture and culture may reference "Style" independent of the time and place that style was developed;  A book may be set in or be about events during a Time Period; It can be about a language or about learning a language.

A properly done BISAC Regional Code would normally map to a Thema Geographical Code.  One warning: Neither Regional Codes nor Geographical Qualifiers are statements about the book's market or publisher sales intent. These should reference the book's subject and nothing else – the content is set in or about described by that qualifier.

BISAC Merchandising Codes have equivalent values on List 5 Special Interest.  List 5 highlight special opportunities for Retailer's – the book's content relates to or sells well in relationship to these events or is of particular concern to or intended to be read by specific groups or religions.

One thing to note is that Audience, Age Ranges and Education values are handled differently in different markets.  In English speaking North America we typically use the ONIX values

  • ONIX Code List 28 for Audience codes
  • Audience Range for age and grade ranges

rather than the Thema List 4 Educational or List 5 Interest Age values.  In the UK and Europe the supply chain would provide them as Thema Subject Codes.  Canada contains two distinct supply chains, the French and English language ones, and the Canadian French Language supply chain tends towards Thema codes for Audience and age (they have strong European connections). Therefore there are "Canadian" values on these lists and you're welcome to use them as supporting both isn't a problem if you see a need (and it doesn't contradict).  Be aware that if your interest is the North American English language market you should not expect retailer uptake of Thema codes for List 4 Education and List 5 Interest Age without checking with them

National Extension Qualifiers

The innovative part of the Thema Subject classification structure is that it can incorporate national values for most Qualifier lists.  Each country, to suit it's individual needs and market may add a national extension value to the already highly granular Thema international qualifier lists.   Other markets may use them or easily ignore them.  Canada has almost 200 Geographical Qualifiers subdividing our country

We expect retailers to use the Qualifier lists to a level of granularity that suits their needs. For example, Canadian retailers may not need the Geographical Qualifier codes provided by German publishers, or German retailers the codes provided by Canadians — unless they find some benefit in using them. The great thing in a hierarchy is that retailers will have the option to data mine to the extent that they find beneficial. 

The two Canadian working groups (BookNet Canada and BTLF) have developed an extensive and detailed list of Geographical qualifiers that extends well past provincial boundaries.  You’ll find much of it between lines 3,922 and 4,070 of the version 1.2 excel file, but there are a number of additions.

Canadian publishers and retailers can engage in a Canadian dialogue about what our industry needs to add to Thema to make it work for us. The system is still being developed, and the working groups hope to receive input and feedback on use going forward. Your participation is the best way for us to identify problems, gaps, and books that defy subject classification in the current scheme.

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.

Thema coding is less restricted.  Obviously if the book is Fiction then the main subject must be a Fiction code – retailers and consumers have to be able to differentiate between fiction and nonfiction – but having identified the book Abraham Lincoln, Vampire Hunter by Seth Grahame-Smith as a Fiction: mashup, you might well use coding that included

Main SubjectSubject CodeQualifier CodeHeading

Fiction: mashup

Horror & supernatural fiction

Autobiography: historical, political & military

3MNQ-US-EAmerican Civil War and Reconstruction (1861–1877)

1KBB-US-SECDistrict of Columbia (Washington D.C.)

Slavery & abolition of slavery

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