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@vocab Names the Vocabulary

The @vocab attribute value may name a controlled vocabulary (defined formally in a taxonomy, ontology, thesaurus, etc.)

Vocabulary Attribute Value
Dublin Core Metadata Initiative dcmi
IPC Codes ipc
MESH headings mesh
United Nations Standard Products and Services Code unspsc

<kwd-group  
  vocab="Inspec"
   <kwd>social networking (online)<kwd>
</kwd-group>
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