German Patent Classification

The German Patent Classification is a patent classification system that was used in several European countries.

The German Patent Office (German: Kaiserliches Patentamt) started developing a classification system for its patent documents in 1877. It was greatly expanded during the following decades and was published in seven editions between 1906 and 1958, first as "Verzeichnis der deutschen Patentklassen" and later as "Gruppeneinteilung der Patentklassen". The abbreviation DPK (for Deutsche Patentklassifikation) is often used, for example in some databases.

Apart from Germany, the DPK was also used in several countries of Scandinavia and central and eastern Europe. Development of the system and active use of it on new publications was discontinued with the introduction of the International Patent Classification (IPC) during the first half of the 1970s, but it is still used in older parts of the patent documentation of some countries.

Between the editions, modifications were published in the form of "Änderungen" and "Ergänzungslieferungen". Between 1958 and 1975 around 40 percent of the original groups were replaced with groups from the emerging IPC. These new IPC-based parts mainly used the IPC group numbering, but kept the original DPK subclass symbols.

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