International Patent Classification - Classification

Classification

Patent publications from all of the Contracting States (and also most others) are each assigned at least one classification term indicating the subject to which the invention relates and may also be assigned further classification and indexing terms to give further details of the contents.

Each classification term consists of a symbol such as A01B 1/00 (which represents "hand tools"). The first letter is the "section symbol" consisting of a letter from A ("Human Necessities") to H ("Electricity"). This is followed by a two digit number to give a "class symbol" (A01 represents "Agriculture; forestry; animal husbandry; trapping; fishing"). The final letter makes up the "subclass" (A01B represents "Soil working in agriculture or forestry; parts, details, or accessories of agricultural machines or implements, in general"). The subclass is then followed by a 1 to 3 digit "group" number, an oblique stroke and a number of at least two digits representing a "main group" or "subgroup". A patent examiner assigns a classification to the patent application or other document at the most detailed level which is applicable to its contents.

A: Human Necessities

B: Performing Operations, Transporting

C: Chemistry, Metallurgy

D: Textiles, Paper

E: Fixed Constructions

F: Mechanical Engineering, Lighting, Heating, Weapons

G: Physics

H: Electricity