1. Index to the Patent Classification
Begin your search with this subject index to the Manual of Classification. This alphabetical index uses common terms to lead you to the classification number(s) relating to your invention. If you do not find your specific invention, look for synonyms, related terms, or words that describe the way it works, its basic function, its method of use, etc.
Paper: Science Section - Patent, Trademark & Copyright Collection
DVD ROM: CASSIS Patents ASSIST (Tools)
Search Patent Classification Index