What are the principles of international patent classification? Which numbering method is used for its marking form?

Beijing Wuyi International Intellectual Property Solution, classification principle: functional classification is combined with application classification, and functional classification is the main one. Considering not only the function of the invention, but also its practical application, giving priority to the function of the invention.

Numbering method of marking: according to the technical theme, set categories, divide the whole technical field into five different levels: department, major category, minor category, major group and small group, and divide all technical fields related to invention patents into eight departments, and mark them with a capital letter in A-H respectively:

Part A: necessities of life (agriculture, light industry and medicine)

Part b: operation and transportation

Part c: chemistry and metallurgy

Part d: textiles and paper making

Part e: fixed buildings

Part F: Mechanical engineering, lighting, heating, weapons and blasting.

Part g: physics

Part h: electrical technology

Each department also has a department composed of information titles. Division is only to further subdivide the content of a certain part, which is convenient for users to search. It is not regarded as a level in classification and has no classification mark.