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Searching the Derwent Registry Number Field

Searches the Derwent Registry Number field within a patent record. Enter one or more numbers connected with search operators.

Derwent Registry Numbers (DRN) are assigned to the most common 2,100 compounds referred to in Derwent WPI. DRN indexing is available in Derwent WPI from 1981 onwards for chemical patents classified in Sections B (Pharmaceuticals) through M (Metallurgy).

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Search Examples

• 1523
• 152*
• 15?3