DWPI manual codes
DWPI Manual Codes is a hierarchical indexing system, intended for use as a patent retrieval and analysis tool. The DWPI Manual Codes index the inventive and significant aspects of an invention, plus its commercial applications.
The DWPI Manual Codes are consistently applied by specialist teams at Clarivate, meaning that they can significantly improve the accuracy of searches compared to using word-based searching, and help to ensure that time is not wasted viewing irrelevant search results. Also, the need to search all possible synonyms and spellings of the topic of interest is avoided by the use of a coding system.
The DWPI Manual Code system is divided into technology Sections by letter in the same way as DWPI Classification. There are more than 27,000 DWPI Manual codes in total, divided broadly as follows:
Sections A-N Chemical Patents Index (CPI), >8,000 codes
Sections P&Q General & Mechanical Patents Index, (GMPI), >3,000 codes
Sections S-X Electrical Patents Index (EPI), >15,000 codes
For more details, see the User Manuals below, or use the Manual Code Lookup tool at the foot of this page
Engineering User Guide (EPI and GMPI)
Manual Code Revision
The DWPI Manual Code hierarchies are revised annually in January to accommodate changes in technology, and provide finer subject matter breakdown.
See below the changes for the January 2025 revision.
Manual Code Revision – Changes 2025
Submit Your Suggestions
Manual Code Revision – January 2026 Proposed Changes
If you would like to comment on the 2026 proposals, or submit a suggestion for possible inclusion in the 2026 DWPI Manual Code Revision, please contact us via email at: scientific.mcrdwpi@clarivate.com. The deadline for the January 2026 revision is Friday 26 September 2025.
