The international patent classification IPC has been used since the first edition 1967+ 1 1, and is revised almost every five years. This is a global patent classification system implemented by intergovernmental organizations.
IPC adopts the principle of combining functional classification with application classification, with functional classification as the main one.
Functional classification refers to the method of classifying objects or methods according to their inherent properties or functions; Application classification is a classification that limits an object or method to a specific field of use.