This document defines a registry of subject authorities for use in the Package Document dc:subject element's opf:authority attribute.
This document is subject to change at any time. The terms defined herein will never be removed, but may be deprecated.
Any use of terms marked [draft] should be considered experimental.
Deprecated term are identified by the label [DEPRECATED]. These terms are no longer recommended for use.
Terms without a label are considered stable.
This registry contains a selection of subject schemes that are commonly used for various types of publications, in various languages, and in various countries. It is not intended to be comprehensive. There are hundreds of possible subject schemes, many of which are discipline specific (e.g., for medicine, computer science, physics, etc.). Preference for inclusion is given to schemes that are broadly useful, but discipline-specific schemes and taxonomies are considered for inclusion if they have a strong support base.