Patents and Standards: Patent documentation

What do patent documents include?

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Most patent documents include:

  • A document number
  • Title of the invention
  • Priority date
  • Inventor’s name and address
  • Assignee’s (organisation’s) name and address
  • Patent attorneys handling the information
  • Abstract
  • Claims
  • Cross references to related applications
  • Local and international patent classification codes
  • Background of the invention
  • Drawings

Patent numbering systems

Further information on what aspects form a patent number, the meaning of patent dates, the use of classification codes and descriptions can be found in the following drop downs.

The format of a patent number depends on the:

1) issuing office, 2) type of patent and 3) when it was issued. 

All patent offices assign a filing or application number when they receive an application, eg AN US 80-207592.

After a patent is granted it is given a final patent number. 
eg US 4,361,601.

Numbers differ according to the country of application which is also indicated by the geographic code.

For example: AN US 80-207592 indicates a publication in the United States, while JP 63,270,598 indicates a Japanese publication.

Patent documents bear several dates (date of application, priority date, date of grant). This will indicate the age of the invention and if it is still under legal protection. If it is no longer legally protected, it can be used without the consent of the patentee.

Dates on patents may include:

  • The filing of application date (priority)
  • The date when the document is first open to public inspection (OPI)
  • The date when it is published (printed copies available)
  • The date when the application is accepted by the patent office
  • The date the patent is granted
  • The date the patent comes into force, takes effect
  • The date the patent expires

Some countries also have an opposition date.

In this example, the date of application (1980) is clearly indicated AN US 80-207592.
For Japanese patents however, the translation is from the year of the Emperor;  ie 25 years less than the Western year. Hence JP 63,270,598 = US 88,270,598

More information on the Asian Patent numbering system can be found in the Asian patent numbering system box below.


Classification codes were developed for use in finding patents (patentability searches) and for assisting in the assignment of patent applications to examiners for examination purposes.

  • Classifications have definitions
  • Classifications have hierarchical relationships to one another

International Patent Classification (IPC) came in to effect in 1971 as more countries joined. The system became more universal, even though many countries continue to use their own scheme as well as the IPC system.

The IPC system divides technology into 8 main sections and over 50,000 subdivisions


The best way to search for a patent is by classification

Classification of an invention eliminates any ambiguity that terminology may create. However, it possible to search for patents using keywords.

  • IPC has current and earlier versions available to browse and search 
  • United States Patent Classification (USPC) system - has about  450 Classes of invention and about 150,000 subclasses. Classifications are typically expressed as "482/1". The first number, 482, represents the class of invention. The number following the slash is the subclass of invention within the class

Patent Classification Help - For more information on patent classification.

Patent documents generally have a fairly uniform structure:

  • The Claims give the essence of what is new
  • The Description gives the background to the invention -  defines the difference between any pre-existent technology and what the invention contributes; as new matter, as a step forward to technology development
  • Often patent documents contain Drawings that illustrate the invention that is claimed

Technological information is disclosed by describing the invention. This is in accordance with the requirements of the applicable patent law and by indicating the claimed novelty and inventiveness by reference to the existing state of the art.

Certain patent documents are published together with a search report showing a series of references which establish the level of novelty of the claimed invention.

Asian patent numbering system