903.02   Basis and Principles of Classification [R-3]

Many of the principles that form the basis of classification used in the U.S. Patent and Trademark Office are set forth in the "Examiner Handbook to the U.S. Patent Classification System" which can be accessed from either the Intranet on the Classification Home Page (http://ptoweb:8081/) or the Internet on the Office of Patent Classification home page (http://www.uspto.gov/web/offices/opc/). Any questions not covered in this handbook can be directed to the Office of Patent Classification.

903.02(a)   New and Revised Classes [R-5]

The establishment of new classes or subclasses and the revision of old classes are done under the guidance of the Technology Center classification contact, as follows:

    • (A) The staff performing the reclassification develops an arrangement of documents which is satisfactory for searching;
    • (B) The definition of the new class or revised class is written or modified;
    • (C) The lines between the class and other classes are drawn up;
    • (D) The subclass definitions are established and definitions of all revised classes and subclasses are included in the classification orders; and
    • (E) The Index of the U.S. Classification System and the Classification Data System files are updated.

Notification of the new class or subclass is published in a classification order. Copies of classification orders are available online to USPTO personnel from the Classification Home Page under the heading Classification Reports. The Classification Home Page (http://ptoweb:8081/) is accessible from the desktop via the Patent Examiner’s Toolkit.

903.02(b)   Scope of a Class

In using any classification system, it is necessary to analyze the organization of the class or classes to be included in the search.

The initial analysis should determine which one or ones of the several types of subject matter (manufacture, art, apparatus, or stock material) are contained in the class being considered.

Further, relative to each type of subject matter, it is necessary to consider each of the various combinations and subcombinations set out below:

Basic Subject Matter Combined with Feature for Some Additional Purpose. The added purpose is in excess of the scope of the subject matter for the class, as defined in the class definition; e.g., adding a sifter to a stone crusher which gives the added function of separating the crushed stone.

Basic Subject Matter Combined with Perfecting Feature. Features may be added to the basic subject matter which do not change the character thereof, but do perfect it for its intended purpose; e.g., an overload release means tends to perfect a stonecrusher by providing means to stop it on overload and thus prevent ruining the machine. However, this perfecting combined feature adds nothing to the basic character of the machine.

Basic Subject Matter. The combination of features necessary and essential to the fundamental character of the subject matter treated; e.g., a stonecrusher requires a minimum number of features as essential before it can function as such.

Subcombinations Specialized to Basic Subject Matter. Each type of basic subject matter may have subcombinations specialized to use therewith; e.g., the crushing element of a stonecrusher.

Subcombinations of General Utility. Each type of basic subject matter may have subcombinations which have utility with other and different types of subject matter; e.g., the machine elements of a stonecrusher. Subcombinations of this character usually are provided for in some general class so that the examiner should determine in each instance where they are classified.

903.02(c)   Establishing Subclasses and Cross-Reference Art Collections [R-5]

Any examiner having the Technology Center Director’s approval to create new subclasses should contact the supervisory patent classifier (SPC) for his or her technology before work is begun. The SPC will assist the examiner in establishing any new subclass by (A) providing appropriate instructions on how to transfer patents from an existing subclass to a new subclass, (B) determining the title and definition of the newly established subclass , and (C) assigning the numeric designation to be placed on the new subclass .

All newly created subclasses will be made official so as to be a part of the defined classification system. New classification data will be added to the Subclass Data File (SDF) and Master Classification File (MCF) as appropriate. Concurrently, all automated classification indices and systems, including the EAST and WEST search tools, will be updated to reflect the new classification changes.