Danish patent classifications

The Danish patent classifications' in the early aero period were administered by the Danish Patent and Trademark Office.

The classifications were the same or very similar to the German one. Notably, klasse 77 refers to aeronautics.

Jørgen Burghardt reports to us that:

The Danish patent office used the German Patent Classification (DPK) for many years. Gruppeneinteilung der Patentklassen (Grouping of the patent classes) started in 1877 in Germany and had seven editions between 1906 and 1958, and with a total new edition in 1975 based on groups from the IPC. The DPK has 89 classes, most with subclasses and subgroups. The Danish patent administration published a printed version in Danish in 1938.

Enclosing categories	Patent category systems
Subcategories	DK 37, DK 65, DK 77
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