Examiner Handbook to the U.S. Patent Classification System

The U.S. Patent Classification system provides for the storage and retrieval of every patent document that a patent examiner needs to review when examining patent applications. Therefore, in the aggregate, the system must be exhaustive of all patentable subject matter under patent laws. Although the system is primarily designed to assist patent examiners performing patentability searches, the system is used by a wide variety of other users, e.g., patent attorneys and agents, people involved in research and development, and the patrons of the Patent and Trademark Resource Center.

This Examiner Handbook is intended for use by U.S. patent examiners, although other users may find it helpful as well.

Table of Contents


I - Organization of Information

II - Aids to Searching or Placement

III - Patent Analysis for Placement into System (Claimed Disclosure)

IV - Determination of a Class for Original Classification or Assignment for Examination

V - Selection of Locus for Searching or Placement

VI - Originals vs. Cross-References

VII - Classification of Design Patents

Addendum - Reclassification in Classes 518 - 585

Appendix A - Structure of the Modern Schedule


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