The Index is intended as an initial means of entry into the classification system and should be particularly useful to those lacking experience in using the classification system and those unfamiliar with the particular technology under consideration. It is an alphabetical list of subject headings referring to specific classes and subclasses of the classification system.
As a first step in locating a field of search, the searcher should look in the Index for the term which best represents the subject matter of interest. If a match is not found, the user should look for terms of approximately the same meaning, for terms of either broader or narrower scope, or for terms which represent a different approach to the subject; i.e. the essential function or effect of the device or the use or application to which the device or composition of matter is put. On finding the identifying numbers of possibly pertinent classes and subclasses in the Index, the user should refer to the Manual of Classification and ascertain from among the existing choices the precise classification (i.e. class and subclass) of the subject interest.
Subject headings in the Index are not an alphabetical inversion of the Manual of Classification. They are a subjective determination of relevant terms, phrases, synonyms, and occasionally even trademarks which have been selected over the years as the best identifying descriptions of products, processes, and apparatus of patent disclosures.
An alphabetical list of the utility class titles and a separate list of the design class titles is located in the front of the Index, directly after the Preface. Searchers may find it useful to scan the titles for topics which may be of interest to them.
The Manual is the listing of the more then 400 main classes and 100,000 subclasses that constitute the patent classification system. It contains a collection of class schedules, a list of the class titles in numerical order by class number and in alphabetical order, a list of the classes by Examining Groups, and a theoretical organization of classes into major groups.
A fundamental principle of the classification system is that each class, or part thereof, is created by first analyzing the claimed disclosures of the U.S. patents and then creating various divisions and subdivisions on the basis of that analysis. All similar subject matter is gathered together in large groupings to create classes. These classes are then subdivided into smaller searchable units called subclasses. The sequence of pattern or arrangement of the subclasses within the classes is called the class schedule.
After the searcher has found the identifying numbers of possibly pertinent classes and subclasses in the Index, the user should refer to those numbers in the Manual of Classification and ascertain from among the existing choices the precise classification (i.e., class and subclass) of the subject interest. If the Index provided both a class and a subclass number, proceed directly to that class and subclass in the Manual. If the Index provided only a class number, the user should turn to the first page of that class in the Manual and then begin to browse the "mainline" subclasses; i.e. any subclass depicted without indentations and presented in all capitals. Start with the first mainline subclass in the selected class and proceed from one mainline class to another until the first one is found which appears to include the subject matter being investigated. Do not consider any of the subclasses depicted in lower case and indented that are subordinate to the mainline subclasses. This is because a subordinate subclass cannot even be considered unless the subclass that it is subordinate to includes the subject matter being investigated. This is true of all levels of subclasses throughout the classification system.
Next the user should scan all of the subordinate subclasses indented one place to the right under the selected mainline subclass until the first one is found which indicates inclusion of the subject matter being investigated. Using this same technique, the searcher should scan the subclasses indented one additional place to the right under the previously identified subordinate subclass until no further levels of indentation are available. It is important to remember that you can not even consider a subordinant subclass unless you have already decided that the subclass that it is subordinant to indicates inclusion of your subject matter. If a subclass does not include your subject matter, proceed to the next subclass of the same level (number of indents) and repeat this procedure until you have exhausted all of the possible subclasses subordinate to your mainline subclass.
Each class and subclass in the Manual of Classification has a precise definition. Whenever doubt arises as to how the Manual defines a class or subclass, or as to the proper subclass choice, the user should consult the classification definition for the class under study. The Classification Definitions supplement the Manual of Classification in that they contain detailed definitions and illustrations of the kind of subject matter that can be found in each class and subclass, the lines of distinction among classes and subclasses, and references to other classes and subclasses having related subject matter. The definitions are available on the ASSIST disc of the CASSIS system or on microfiche.
The Original classification identifies, in the opinion of the patent examiner, the most substantial aspect of the patent. It is always the first classification number listed on the patent. All of the other classifications listed on the patent are called Cross Reference classifications and identify all of the other aspects of the patent. There is only one Original Classification per patent but there can be any number of Cross Reference classifications. If it can be assumed that the classification number being searched represents one of the most substantial aspects of the idea being searched, it stands to reason that other patents issued with this classification as the Original classification will be more similar to the idea being searched then patents issued with this classification as a Cross Reference designation. For this reason, examine the patents on the list with an Original designation first, especially if there are a large number of patents to be examined. These are indicated by the presence of an "O" to the right of the patent number on the list of patents obtained from the &qquot;Classification-By Subclass" file. If there are no conflicting patents in the group with Original designations, then go back and examine the Cross Reference designations also. These are indicated by the presence of an "X" to the right of the patent number. Remember that you must examine all of the patents on each list to do a complete patent search.
CASSIS (Classification And Search System Information Service) is a computer system provided to libraries in the Depository Library program to assist users with their patent and trademark searches. CASSIS files include a Bibliographic Information File containing brief information on patents granted by the U.S. since 1969; the Classification Information files which provide classification information on patents including the complete list of patents granted to any class and subclass since 1790; the ASSIST files which contain the Classification Definitions, the Manual of Classification and the Index in electronic format, and other files related to patent information. CASSIS is a CD-ROM system and is updated every two or three months, depending on the file.
