Thema Subject Codes

Related pages

Thema Basics

Thema Implementation: Practical Considerations

Thema ONIX Sample

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


Thema is a subject classification system designed to support trade book publishing. Like the familiar BISAC or BIC systems, the idea is not to create an exhaustive subject system to describe all possible subjects (formal library subject systems do that better). A book trade subject system is more contained, easier to learn and apply. It only supports classifications where a reasonable number of published books exist.

What differentiates Thema from BISAC or BIC is Thema supports both international and national marketing of books while BISAC and BIC represent the subject needs of a single market.  Thema does this by combining a single international Subject Category list with six Qualifier Code lists. Each Qualifier Code lists provide generic values common to all markets, but when appropriate Qualifier lists can include country specific codes – National Extensions -- that allow each list to be subdivided as granular as the individual country needs. (See Thema Basics for details)  Other countries (or markets) can use or ignore that detail because the code system is hierarchical and the source "international codes" are always available.   Thema works for international markets and each country can personalize the lists for use within their own supply chain. 

Thema is recommended for Canadian Publishers

For BookNet Canada it's a no brainer:  Thema offers better access to markets outside of North America and better coding options for Canada. Canadian publishers should use Thema.  Unfortunately BISAC Subject Codes continue to be used almost exclusively in the US and by Canadian retailers. You can't ignore or stop using BISAC, but the two systems are fairly compatible and the BISAC to Thema Translator can be a big help in classification of books and back list.

EDItEUR Thema Instructions and Codelists

Thema Version 1.3 is available from EDItEUR:

  • The Thema Basic User Instructions is a good starting document for anyone working on subject coding. It provides an introduction to the scheme, some general principles for best practices, and brief definitions of all of the subject codes and qualifier lists.
  • EDItEUR supports on-line lookup browser for Thema Codes that is available here.  There is a one-page instruction sheet Thema browser.pdf.

Mapping from BISAC to Thema

BISG and BookNet Canada have released a mapping from BISAC subjects to Thema subjects. A hard copy is available as part of your BISAC Subject package purchased from BISG or it's available here as a look up for both individual records and ISBN based BISAC subject lists

BookNet Canada Support

BookNet Canada has organized a Thema news group for English-language Canadian publishers. If you would like to join, please contact  This group can inform and make suggestion to BNC's Bibliographic Committee.  It represents the Canadian English Language National Group that reports to Thema International.  

Make suggestions!  Try not to re-write the system make it compatible with your publishing program but if you can demonstrate that there are a group of books that share a subject not listed that value can and should be added to Thema, and for that matter BISAC.

Please let us know at

French-Language Canadian Publishers

The BTLF is your resource for information about the transition to Thema. You can contact the BTLF directly for further information.