Subject classification and code（GBT/13745-2009）vocabulary

The classification and code standard of disciplines (GB/T 13745-2009) is the current national classification standard of disciplines, which defines the classification of disciplines to the first, second and third levels, with 62 primary disciplines or discipline groups, 676 secondary disciplines or discipline groups and 2382 third-level disciplines. This discipline classification lexicon, based on the national standard, standardizes the description of discipline classification subject terms, provides a semantically unified lexicon specification for the configuration of disciplines to which the current scientific data resources belong, and describes the hierarchical relationship between discipline classifications through the hypernym and hyponym.