International Patent Classification

1. Definition

The IPC is a hierarchical system of classifying technology by dividing

them into a range of sections, classes, subclasses and groups.

 

2. Principle of classifying

The IPC employs the principle of classifying inventions according to their

intrinsic nature (the “function‐oriented” principle), rather than their possible

“applications”. Still, the IPC contains both function‐oriented places and

application places and is a combined function/application classification

system in which the function takes precedence.

 

An illustration of a complete classification symbol of IPC is shown below :

A                  21              B              1     /    08

|                   |              |              |           |

Section          Class          Subclass      Main group   Sub group

 

The classification scheme containing about 70,000 classification symbols is

arranged in a hierarchical, tree‐like structure.

(1) Section: The lowest hierarchical levels are the eight sections of the

IPC corresponding to very broad technical fields. (Section A=Human

Necessities)

(2) Class: Sections are subdivided into 120 classes in the eighth edition

of the IPC. (Class A 21=Baking; Edible dough)

(3) Subclass: Classes are further subdivided into more than 600

subclasses. (Subclass A 21 B=Bakers’ ovens; Machines or equipment

for baking)

(4) Main group: Main group symbols always end with “/00”. (Main group

A 21 B 1/00 = Bakers’ ovens)

(5) Sub group: The hierarchy of the subgroups under main groups is

designated by dots preceding the titles of the entries.

Main group A 21 B 1/00 (“Bakers’ oven”) is divided into 19 subgroups,

the first four of which are the following:

A 21 B 1/02 . characterized by the heating arrangements

A 21 B 1/04 .. Ovens heated by fire before baking only

A 21 B 1/06 .. Ovens heated by radiators

A 21 B 1/08 … by steam‐heated radiators

As can be seen from the above example, not all the subgroups are on

the same hierarchical level; the highest are preceded by one dot, the

lower‐according to their level‐by two, three, four or more dots.