The new indexing can help you make your searches for biological information more precise. New fields provide in-depth indexing for major concepts, organisms, chemicals and drugs, diseases, geographic terms, and other aspects of articles.
Relational indexing allows index terms to express relationships between concepts.
The new index terms have replaced Concept Codes and Biosystematic Codes. Over 500,000 journal articles and other documents from over 6,000 journals and other sources are indexed each year.